Rhabdocœla
Rhab•do•cœ"la (rab•do•se"la), n. pl. [NL., fr. Gr. "ra•bdos a rod + koi^los hollow.] (Zoöl.) A suborder of Turbellaria including those that have a simple cylindrical, or saclike, stomach, without an intestine.

Rhabdocœlous
Rhab•do•cœ"lous (-lus), a. (Zoöl.) Of or pertaining to the Rhabdocœla.

Rhabdoidal
Rhab•doid´al, a. See Sagittal.

Rhabdology
Rhab•dol´o•gy, n. Same as Rabdology.

Rhabdophora
Rhab•doph´o•ra, n. pl. [NL., fr. Gr. "ra•bdos a rod + to bear.] (Zoöl.) An extinct division of Hydrozoa which includes the graptolities.

Rhabdopleura
Rhab•do•pleu´ra, n. [NL., fr. Gr. "ra•bdos a rod + the side.] (Zoöl.) A genus of marine Bryozoa in which the tubular cells have a centralchitinous axis and the tentacles are borne on a bilobed lophophore. It is the type of the order Pterobranchia, or Podostomata

Rhabdosphere
Rhab´do•sphere, n. [Gr. "ra•bdos a rod + E. sphere.] A minute sphere composed of rhabdoliths.

Rhachialgia
Rha•chi•al´gi•a, n. [NL.] See Rachialgia.

Rhachiglossa
Rhach•i•glos´sa, n. pl. [NL. See Rhachis, and Glossa.] (Zoöl.) A division of marine gastropods having a retractile proboscis and three longitudinal rows of teeth on the radula. It includes many of the large ornamental shells, as the miters, murices, olives, purpuras volutes, and whelks. See Illust. in Append.

Rhachiodont
Rha´chi•o•dont, a. [Gr. "ra•chis, -ios, the spine +,, a tooth.] (Zoöl.) Having gular teeth formed by a peculiar modification of the inferior spines of some of the vertebrae, as certain South African snakes ( Dasypeltis) which swallow birds’ eggs and use these gular teeth to crush them.

Rhachis
Rha´chis, n. ; pl. E. Rhachises (#), L. Rhachides (#). [See Rachis.] [Written also rechis.]
1. (Anat.) The spine.
2. (Bot.) (a) The continued stem or midrib of a pinnately compound leaf, as in a rose leaf or a fern. (b) The principal axis in a raceme, spike, panicle, or corymb.
3. (Zoöl.) (a) The shaft of a feather. The rhachis of the after-shaft, or plumule, is called the hyporhachis. (b) The central cord in the stem of a crinoid. (c) The median part of the radula of a mollusk. (d) A central cord of the ovary of nematodes.

Rhadamanthus
Rhad•a•man´thus, n. [L., fr. Gr. .] (Greek Mythol.) One of the three judges of the infernal regions; figuratively, a strictly just judge.

Rhaetian
Rhae´ti•an, a & n. Rhetain.

Rhaetic
Rhae´tic, a. [L. Rhaeticus Rhetian.] (Geol.) Pertaining to, or of the same horizon as certain Mesozoic strata of the Rhetian Alps. These strata are regarded as closing the Triassic period. See the Chart of Geology.

Rhamadan
Rham•a•dan´, n. See Ramadan.

Rhamnus
Rham´nus, n. [NL., from Gr. "ra•mnos a kind of prickly shrub; cf. L. rhamnos.] (Bot.) A genus of shrubs and small trees; buckthorn. The California Rhamnus Purshianus and the European R. catharticus are used in medicine. The latter is used for hedges.

Rhamphorhynchus
Rham•pho•rhyn´chus, n. [NL., fr. Gr. "ra•mfos a beak + snout.] (Paleon.) A genus of pterodactyls in which the elongated tail supported a leathery expansion at the tip.

Rhamphotheca
Rham•pho•the´ca, n. ; pl. Rhamphothecae (#). [NL., fr. Gr "ra•mnos a beak + a case.] (Zoöl.) The horny covering of the bill of birds.

Rhaphe
Rha´phe, n. [NL., fr. Gr. seam, fr. to sew. ] (Bot.) The continuation of the seed stalk along the side of an anatropous ovule or seed, forming a ridge or seam. [Written also raphe.] Gray.

Rhaphides
Rhaph´i•des, n. pl. [NL., fr. Gr.,, a needle, F. raphides.] (Bot.) Minute transparent, often needle-shaped, crystals found in the tissues of plants. [Written also raphides.]

Rhaponticine
Rha•pon´ti•cine, n. [L. rhaponticum rhubarb. See Rhubarb.] (Chem.) Chrysophanic acid.

Rhapsodist
Rhap´so•dist, n. [From Rhapsody.]
1. Anciently, one who recited or composed a rhapsody; especially, one whose profession was to recite the verses of Hormer and other epic poets.
2. Hence, one who recites or sings poems for a livelihood; one who makes and repeats verses extempore.
"The same populace sit for hours listening to rhapsodists who recite Ariosto." Carlyle.
3. One who writes or speaks disconnectedly and with great excitement or affectation of feeling. I. Watts.

Rhapsodomancy
Rhap´so•do•man•cy, n. [ Rhapsody + -mancy.] Divination by means of verses.

Rhapsody
Rhap´so•dy, n. ; pl. Rhapsodies (#). [F. rhapsodie, L. rhapsodia, Gr. "rapsw,di•a, fr. "rapsw,do•s a rhapsodist; "ra•ptein to sew, stitch together, unite + ’w,dh• a song. See Ode.]
1. A recitation or song of a rhapsodist; a portion of an epic poem adapted for recitation, or usually recited, at one time; hence, a division of the Iliad or the Odyssey; — called also a book.
2. A disconnected series of sentences or statements composed under excitement, and without dependence or natural connection; rambling composition. "A rhapsody of words." Shak. "A rhapsody of tales." Locke.
3. (Mus.) A composition irregular in form, like an improvisation; as Liszt’s "Hungarian Rhapsodies." { Rhat´a•ny, Rhat´an•hy }, n. [Sp. ratania, rataña, Peruv. rataña.] The powerfully astringent root of a half- shrubby Peruvian plant ( Krameria triandra). It is used in medicine and to color port wine. [Written also ratany.] Savanilla rhatany, the root of Krameria Ixina, a native of New Granada.

Rheae
Rhe´ae, n. pl. [NL.] (Zoöl.) A suborder of struthious birds including the rheas.

Rheeboc
Rhee´boc, n. [D. reebok roebuck.] (Zoöl.) The peele. [Written also reebok.]

Rheic
Rhe´ic, a. [NL. Rheum rhubarb, Gr. See Rhubarb.] (Chem.) Pertaining to, or designating, an acid (commonly called chrysophanic acid) found in rhubarb ( Rheum). [Obsoles.]

Rheinberry
Rhein´ber•ry, n. [G. rheinbeere.] (Bot.) One of the berries or drupes of the European buckthorn; also the buckthorn itself.

Rhematic
Rhe•mat´ic, a. [Gr. of or for a verb, fr.,, a sentence. See Rhetoric.] (Gram.) Having a verb for its base; derived from a verb; as rhematic adjectives. Ftzed. Hall.

Rhematic
Rhe•mat´ic, n. The doctrine of propositions or sentences. Coleridge.

Rhemish, a. Of or pertaining to Rheimis, or Reima, in France. Rhemish Testament, the English version of the New Testament used by Roman Catholics. See Douay Bible.

Rheochord
Rhe´o•chord, n. [Gr. "rei^n to flow + chord.] (Elec.) A metallic wire used for regulating the resistance of a circuit, or varying the strength of an electric current, by inserting a greater or less length of it in the circuit.

Rheocrat
Rhe´o•crat, n. [Gr. "rei^n to flow + kratei^n to rule.] (Elec.) A kind of motor speed controller permitting of very gradual variation in speed and of reverse. It is especially suitable for use with motor driven machine tools.

Rheometer
Rhe•om´e•ter, n. [Gr. "rei^n to flow + -meter.] [Written also reometer.]
1. (Physics) An instrument for measuring currents, especially the force or intensity of electrical currents; a galvanometer.
2. (Physiol.) An instrument for measuring the velocity of the blood current in the arteries.

Rheometric
Rhe•o•met´ric, a. Of or pertaining to a rheometer or rheometry. Lardner.

Rheometry
Rhe•om´e•try, n.
1. The measurement of the force or intensity of currents.
2. (Math.) The calculus; fluxions. [R.]

Rheomotor
Rhe´o•mo•tor, n. [Gr. "rei^n to flow + E. motor.] (Elec.) Any apparatus by which an electrical current is originated. [R.]

Rheophore
Rhe´o•phore, n. [Gr. "rei^n to flow + to carry.] (Elec.) (a) A connecting wire of an electric or voltaic apparatus, traversed by a current. (b) One of the poles of a voltaic battery; an electrode.

Rheoscope
Rhe´o•scope, n. [Gr. "rei^n to flow + -scope.] (Physics) An instrument for detecting the presence or movement of currents, as of electricity.

Rheostat
Rhe´o•stat, n. [Gr. "rei^n + stato•s standing still.] (Elec.) A contrivance for adjusting or regulating the strength of electrical currents, operating usually by the intercalation of resistance which can be varied at will. Wheatstone. — Rhe•o•stat´ic (#), a.

Rheotome
Rhe´o•tome (-tom), n. [Gr. "rei^n to flow + te•mnein to cut.] (Elec.) An instrument which periodically or otherwise interrupts an electric current. Wheatstone.

Rheotrope
Rhe´o•trope, n. [Gr. "rei^n to flow + to turn.] (Elec.) An instrument for reversing the direction of an electric current. [Written also reotrope.]

Rhesus
Rhe´sus, n. [L. Rhesus, a proper name, Gr. .] (Zoöl.) A monkey; the bhunder.

Rhetian
Rhe´ti•an, a. [L. Rhaetius, Raetius: cf. F. rhetien.] Pertaining to the ancient Rhaeti, or Rhaetians, or to Rhaetia, their country; as the Rhetian Alps, now the country of Tyrol and the Grisons.

Rhetic
Rhe´tic, a. (Min.) Same as Rhaetic.

Rhetoric
Rhet´o•ric, n. [F. rhetorique, L. rhetorica, Gr. (sc. ), fr. rhetorical, oratorical, fr. orator, rhetorician; perhaps akin to E. word; cf. to say.]
1. The art of composition; especially, elegant composition in prose.
2. Oratory; the art of speaking with propriety, elegance, and force. Locke.
3. Hence, artificial eloquence; fine language or declamation without conviction or earnest feeling.
4. Fig. : The power of persuasion or attraction; that which allures or charms.
"Sweet, silent rhetoric of persuading eyes." Daniel.

Rhetorical
Rhe•tor´ic•al, a. [L. rhetoricus, Gr. . See Rhetoric.] Of or pertaining to rhetoric; according to, or exhibiting, rhetoric; oratorical; as the rhetorical art; a rhetorical treatise; a rhetorical flourish.
"They permit him to leave their poetical taste ungratified, provided that he gratifies their rhetorical sense." M. Arnold. — Rhe•tor´ic•al•ly, adv. — Rhe•tor´ic•al•ness, n.

Rhetorician
Rhet•o•ri´cian, n. [Cf. F. rhetoricien.]
1. One well versed in the rules and principles of rhetoric.
"The understanding is that by which a man becomes a mere logician and a mere rhetorician." F. W. Robertson.
2. A teacher of rhetoric.
"The ancient sophists and rhetoricians, which ever had young auditors, lived till they were an hundred years old." Bacon.
3. An orator; specifically, an artificial orator without genuine eloquence; a declaimer. Macaulay.

Rhetorician
Rhet•o•ri´cian, a. Suitable to a master of rhetoric. "With rhetorician pride." Blackmore.

Rhetorize
Rhet´o•rize (ret"o•riz), v. i. [ imp. & p. p. Rhetorized (- rizd); p. pr. & vb. n. Rhetorizing (- ri•zing).] To play the orator. Colgrave.

Rhetorize
Rhet´o•rize, v. t. To represent by a figure of rhetoric, or by personification. Milton.

Rheum
Rhe´um (re"um), n. [NL., from L. Rha the river Volga, on the banks of which it grows. See Rhubarb.] (Bot.) A genus of plants. See Rhubarb.

Rheum (rum), n. [OF. reume, rheume, F. rhume a cold,, L. rheuma rheum, from Gr., fr. "rei^n to flow, akin to E. stream. See Stream, n. , and cf. Hemorrhoids.] (Med.) A serous or mucous discharge, especially one from the eves or nose.
"I have a rheum in mine eyes too." Shak. Salt rheum. (Med.) See Salt rheum, in the Vocab.

Rheumatism
Rheu´ma•tism, n. [L. rheumatismus rheum, Gr., fr. to have or suffer from a flux, fr. rheum: cf. F. rheumatisme. See 2d Rheum.] (Med.) A general disease characterized by painful, often multiple, local inflammations, usually affecting the joints and muscles, but also extending sometimes to the deeper organs, as the heart. Inflammatory rheumatism (Med.), acute rheumatism attended with fever, and attacking usually the larger joints, which become swollen, hot, and very painful. — Rheumatism root. (Bot.) See Twinleaf.

Rheumatismoid
Rheu•ma•tis´moid, a. [ Rheumatism + -oid.] (Med.) Of or resembling rheum or rheumatism.

Rheumic
Rheum´ic, a. (Med.) Pertaining to, or characterized by, rheum. Rheumic diathesis. See Dartrous diathesis, under Dartrous.

Rhigolene
Rhig´o•lene, n. [Gr. cold + L. oleum oil.] (Chem.) A mixture of volatile hydrocarbons intermediate between gsolene and cymogene. It is obtained in the purification of crude petroleum, and is used as a refregerant.

Rhime, n. See Rhyme. [Obs.]

Rhinaster
Rhi•nas´ter, n. [NL., fr. Gr.,, nose + star.] (Zoöl.) The borele.

Rhine, n. [AS. ryne. See Run.] A water course; a ditch. [Written also rean.] [Prov. Eng.] Macaulay.

Rhinencephalon
Rhi•nen•ceph´a•lon, n. ; pl. Rhinencephala (#). [NL., fr. Gr.,, the nose + the brain.] (Anat.) The division of the brain in front of the prosencephalon, consisting of the two olfactory lobes from which the olfactory nerves arise. The term is sometimes used for one of the olfactory lobes, the plural being used for the two taken together.

Rhinestone
Rhine´stone, n. [Cf. G. rheinkiesel Rhine quartz.] A colorless stone of high luster, made of paste. It is much used as an inexpensive ornament.

Rhinitis
Rhi•ni´tis, n. [NL., fr. Gr. ., the nose + -itis.] (Med.) Infllammation of the nose; esp., inflammation of the mucous membrane of the nostrils.

Rhino
Rhi•no, n. [Etymol. uncertain.] Gold and silver, or money. [Cant] W. Wagstaffe.
"As long as the rhino lasted." Marryat.

Rhino-
Rhi´no-. A combining form from Greek,, the nose, as in rhinolith, rhinology. { Rhi•no•ce´ri•al, Rhi•no•cer´ic•al } a. (Zoöl.) Of or pertaining to the rhinoceros; resembling the rhinoceros, or his horn. Tatler.

Rhinoceros
Rhi•noc´e•ros, n. [L., fr. Gr., ; ., the nose + a horn: cf. F. rhinoceros. See Horn.] (Zoöl.) Any pachyderm belonging to the genera Rhinoceros, Atelodus, and several allied genera of the family Rhinocerotidae, of which several living, and many extinct, species are known. They are large and powerful, and usually have either one or two stout conical median horns on the snout. The Indian, or white, and the Javan rhinoceroses ( Rhinoceros Indicus and R. Sondaicus) have incisor and canine teeth, but only one horn, and the very thick skin forms shieldlike folds. The two or three African species belong to Atelodus, and have two horns, but lack the dermal folds, and the incisor and canine teeth. The two Malay, or East Indian, two- horned species belong to Ceratohinus, in which incisor and canine teeth are present. See Borele, and Keitloa. Rhinoceros auk (Zoöl.), an auk of the North Pacific ( Cerorhina monocrata) which has a deciduous horn on top of the bill. — Rhinoceros beetle (Zoöl.), a very large beetle of the genus Dynastes, having a horn on the head. — Rhinoceros bird. (Zoöl.) (a) A large hornbill ( Buceros rhinoceros), native of the East Indies. It has a large hollow hornlike process on the bill. Called also rhinoceros hornbill. See Hornbill. (b) An African beefeater ( Buphaga Africana). It alights on the back of the rhinoceros in search of parasitic insects.

Rhinocerotic
Rhi•noc•e•rot´ic, a. Of or pertaining to the rhinoceros. [R.] { Rhi´no•lite, Rhi´no•lith } n. [ Rhino- + -lite, -lith.] (Med.) A concretion formed within the cavities of the nose.

Rhinological
Rhi•no•log´ic•al, a. Of or pertaining to rhinology.

Rhinologist
Rhi•nol´o•gist, n. One skilled in rhinology.

Rhinology
Rhi•nol´o•gy, n. [ Rhino- + -logy.] The science which treats of the nose, and its diseases.

Rhinolophid
Rhi•nol´o•phid, n. [ Rhino- + Gr. crest.] (Zoöl.) Any species of the genus Rhinilophus, or family Rhinolophidae, having a horseshoe-shaped nasal crest; a horseshoe bat.

Rhinolophine
Rhi•nol´o•phine, a. (Zoöl.) Like or pertaining to the rhinolophids, or horseshoe bats.

Rhinophore
Rhi´no•phore, n. [ Rhino- + Gr. to bear.] (Zoöl.) One of the two tentacle-like organs on the back of the head or neck of a nudibranch or tectibranch mollusk. They are usually retractile, and often transversely furrowed or plicate, and are regarded as olfactory organs. Called also dorsal tentacles. See Illust. under Pygobranchia, and Opisthobranchia.

Rhinoplasty
Rhi´no•plas•ty, n. [ Rhino- + -plasty: cf. F. rhinoplastie.] Plastic surgery of the nose to correct deformity or to replace lost tissue. Tissue may be transplanted from the patient’s cheek, forehead, arm, etc., or even from another person.

Rhinopome
Rhi´no•pome, n. [ Rhino- + Gr. pw^ma a lid. ] (Zoöl.) Any old-world bat of the genus Rhinopoma. The rhinopomes have a long tail extending beyond the web, and inhabit caves and tombs.

Rhinoscleroma
Rhi•no•scle•ro´ma, n. [ Rhino- + scleroma.] (Med.) A rare disease of the skin, characterized by the development of very hard, more or less flattened, prominences, appearing first upon the nose and subsequently upon the neighboring parts, esp. the lips, palate, and throat. J. V. Shoemaker.

Rhinoscope
Rhi´no•scope, n. [ Rhino- + -scope.] A small mirror for use in rhinoscopy.

Rhinoscopic
Rhi•no•scop´ic, a. (Physiol.) Of or pertaining to rhinoscopy.

Rhinoscopy
Rhi•nos´co•py, n. [ Rhino- + -scopy.] (Physiol.) The examination or study of the soft palate, posterior nares, etc., by means of a laryngoscopic mirror introduced into the pharynx.

Rhinotheca
Rhi•no•the´ca, n. ; pl. Rhinothecae (#). [NL., from gr.,, the nose + case.] (Zoöl.) The sheath of the upper mandible of a bird.

Rhipidoglossa
Rhi•pi•do•glos´sa, n. pl. [NL., fr. Gr. a fan + a tongue.] (Zoöl.) A division of gastropod mollusks having a large number of long, divergent, hooklike, lingual teeth in each transverse row. It includes the scutibranchs. See Illustration in Appendix.

Rhipipter
Rhi•pip´ter, n. [Gr. a fan + wing.] (Zoöl.) One of the Rhipiptera, a group of insects having wings which fold like a fan; a strepsipter.

Rhipipteran
Rhi•pip´ter•an, n. (Zoöl.) Same as Rhipipter.

Rhizine
Rhi´zine, n. [Gr. root.] (Bot.) A rootlike filament or hair growing from the stems of mosses or on lichens; a rhizoid.

Rhizocarpous
Rhi•zo•car´pous, a. [Gr. root + fruit.] (Bot.) Having perennial rootstocks or bulbs, but annual flowering stems; — said of all perennial herbs.

Rhizocephala
Rhi•zo•ceph´a•la, n. pl. [NL., fr. Gr. root + head.] (Zoöl.) A division of Pectostraca including saclike parasites of Crustacea. They adhere by rootlike extensions of the head. See Illusration in Appendix.

Rhizodont
Rhiz´o•dont, n. [Gr. root +,, a tooth.] (Zoöl.) A reptile whose teeth are rooted in sockets, as the crocodile.

Rhizogan
Rhiz´o•gan, a. [Gr. root + -gen: cf. F. rhizogène.] (Bot.) Prodicing roots.

Rhizogen
Rhiz´o•gen, n. (Bot.) One of a proposed class of flowering plants growning on the roots of other plants and destitute of green foliage.

Rhizoid
Rhi´zoid, n. [Gr. root + -oid.] (Bot.) A rootlike appendage.

Rhizoma
Rhi•zo´ma, n. ; pl. Rhizomata (#). [NL.] (Bot.) SAme as Rhizome.

Rhizome
Rhi•zome´, n. [Gr. the mass of roots (of a tree), a stem, race, fr. to make to root, pass., to take root, fr. a root: cf. F. rhizome.] (Bot.) A rootstock. See Rootstock.

Rhizophagous
Rhi•zoph´a•gous, a. [Gr. ; a root + to eat.] Feeding on roots; root- eating.

Rhizophora
Rhi•zoph´o•ra, n. [NL. See Rhizophorous.] (Bot.) A genus of trees including the mangrove. See Mangrove.

Rhizopod
Rhiz´o•pod, n. (Zoöl.) One of the Rhizopoda. The rhizopods belonging to the Radiolaria and Foraminifera have been of great geological importance, especially in the Cretaceous and Tertiary periods. Chalk is mostly made from the shells of Foraminifera. The nummulites are the principal ingredient of a limestone which is of great extent in Europe and Asia, and is the material of which some of the pyramids of Egypt are made. The shells are abundant in deepsea mud, and are mostly minute, seldom larger than a small grain of sand, except in the case of the nummulities, which are sometimes an inch in diameter.

Rhizopoda
Rhi•zop´o•da, n. pl. [NL., fr. Gr. a root + -poda.] (Zoöl.) An extensive class of Protozoa, including those which have pseudopodia, by means of which they move about and take their food. The principal groups are Lobosa (or Amœbea), Helizoa, Radiolaria, and Foraminifera (or Reticularia). See Protozoa.

Rhizostomata
Rhi•zo•stom´a•ta, n. pl. [NL., fr. Gr. a root +,, a mouth.] (Zoöl.) A suborder of Medusae which includes very large species without marginal tentacles, but having large mouth lobes closely united at the edges. See Illust. in Appendix.

Rhizostome
Rhiz´o•stome, n. (Zoöl.) One of the Rhizostomata.

Rhizotaxis
Rhi•zo•tax´is, n. [NL., fr. Gr. a root + arrangement.] (Bot.) The arrangement of the roots of plants.

Rhob (rob), n. See 1st Rob.

Rhodanate
Rho´da•nate, n. (Chem.) A salt of rhodanic acid; a sulphocyanate. [Obsoles.]

Rhodanic
Rho•dan´ic, a. [Gr. the rose.] (Chem.) Pertaining to, or designating, an acid (commonly called sulphocyanic acid) which frms a red color with ferric salts. [Obsoles.]

Rhodeoretin
Rho•de•o•re´tin, n. [Gr. the rose + resin.] (Chem.) Same as Convolvuln.

Rhodic
Rho´dic, a. (Chem.) Of or pertaining to rhodium; containing rhodium.

Rhodium
Rho´di•um, n. [NL., fr. Gr. "ro•don the rose. So called from the rose-red color of certain of its solutions. See Rhododendron.] (Chem.) A rare element of the light platinum group. It is found in platinum ores, and obtained free as a white inert metal which it is very difficult to fuse. Symbol Rh. Atomic weight 104.1. Specific gravity 12.

Rhodochrosite
Rho•do•chro´site, n. [Gr. "ro•don the rose + a coloring.] (Min.) Manganese carbonate, a rose-red mineral sometimes occuring crystallized, but generally massive with rhombohedral cleavage like calcite; — called also dialogite.

Rhodocrinite
Rho•doc´ri•nite, n. [Gr. "ro•don rose + lily.] (Paleon.) A rose encrinite.

Rhododendron
Rho•do•den´dron, n. [L., fr. Gr. "rodo•dendron, literally, rose tree; "ro•don rose + de•ndron tree. See Rose.] (Bot.) A genus of shrubs or small trees, often having handsome evergreen leaves, and remarkable for the beauty of their flowers; rosebay.

Rhodophane
Rho´do•phane, n. [Gr. "ro•don the rose + to show.] (Physiol.) The red pigment contained in the inner segments of the cones of the retina in animals. See Chromophane. W. KÜhne.

Rhomb, n. [L. rhombus, Gr. rhomb, a spinning top, magic wheel, fr. to turn or whirl round, perhaps akin to E. wrench: cf. F. rhombe. Cf. Rhombus, Rhumb.]
1. (Geom.) An equilateral parallelogram, or quadrilateral figure whose sides are equal and the opposite sides parallel. The angles may be unequal, two being obtuse and two acute, as in the cut, or the angles may be equal, in which case it is usually called a square.
2. (Geom.) A rhombohedron. Fresnel’s rhomb (Opt.), a rhomb or oblique parallelopiped of crown or St. Gobain glass so cut that a ray of light entering one of its faces at right angles shall emerge at right angles at the opposite face, after undergoing within the rhomb, at other faces, two reflections. It is used to produce a ray circularly polarized from a plane-polarized ray, or the reverse. Nichol.

Rhombic
Rhom´bic, a.
1. Shaped like a rhomb.
2. (Crystallog.) Same as Orthorhombic.

Rhomboganoidei
Rhom•bo•ga•noi´de•i, n. pl. [NL.] (Zoöl.) Same as Ginglymodi.

Rhombohedron
Rhom•bo•he´dron, n. [NL., fr. Gr. rhomb + seat, base.] (Geom. & Crystallog.) A solid contained by six rhomboids; a parallelopiped.

Rhomboid
Rhom´boid (rom"boid), n. [Gr. rhomboidal; rhomb + e’i^dos shape: cf. F. rhomboïde.] (Geom.) An oblique-angled parallelogram like a rhomb, but having only the opposite sides equal, the length and with being different.

Rhomboid
Rhom´boid (rom"boid), a. Same as Rhomboidal.

Rhomboides
Rhom•boid´es, n. A rhomboid. [R.] Milton.

Rhomboid-ovate
Rhom•boid-o´vate, a. Between rhomboid and ovate, or oval, in shape.

Rhombus
Rhom´bus, n. [L.] Same as Rhomb, 1.

Rhonchial
Rhon´chi•al, a. (Med.) Of or pertaining to a rhonchus; produced by rhonchi. Rhonchial fremitus. [L. fremitus a dull roaring or murmuring.] (Med.) A vibration of the chest wall that may be felt by the hand laid upon its surface. It is caused in the production of rhonchi in the bronchial tubes.

Rhonchisonant
Rhon•chis´o•nant, a. [L. rhonchus a snoring + sonans, p. pr. of sonare to sound.] Making a snorting noise; snorting. [R.]

Rhonchus
Rhon´chus, n. ; pl. Rhonchi (#). [L., a snoring, a croaking.] (Med.) An adventitious whistling or snoring sound heard on auscultation of the chest when the air channels are partially obstructed. By some writers the term rhonchus is used as equivalent to râle in its widest sense. See Râle.

Rhopalium
Rho•pa´li•um, n. ; pl. Rhopalia (#). [NL.] (Zoöl.) One of the marginal sensory bodies of medusae belonging to the Discophora.

Rhopalocera
Rhop•a•loc´e•ra, n. pl. [NL., from Gr. a club + ahorn.] (Zoöl.) A division of Lepidoptera including all the butterflies. They differ from other Lepidoptera in having club-shaped antennae.

Rhotacism
Rho´ta•cism, n. [Gr. "rwtaki•zein to use the letter r (ρ) overmuch: cf. F. rhotacisme.] An oversounding, or a misuse, of the letter r; specifically (Phylol.), the tendency, exhibited in the Indo-European languages, to change s to r, as wese to were.

Rhubarb
Rhu´barb, n. [F. rhubarbe, OF. rubarbe, rheubarbe, reubarbare, reobarbe, LL. rheubarbarum for rheum barbarum, Gr. (and ) rhubarb, from the river Rha (the Volga) on whose banks it grew. Originally, therefore, it was the barbarian plant from the Rha. Cf. Barbarous, Rhaponticine.]
1. (Bot.) The name of several large perennial herbs of the genus Rheum and order Polygonaceae.
2. The large and fleshy leafstalks of Rheum Rhaponticum and other species of the same genus. They are pleasantly acid, and are used in cookery. Called also pieplant.
3. (Med.) The root of several species of Rheum, used much as a cathartic medicine. Monk’s rhubarb. (Bot.) See under Monk. — Turkey rhubarb (Med.), the roots of Rheum Emodi.

Rhumb, n. [F. rumb, Sp. rumbo, or Pg. rumbo, rumo, probably fr. Gr. a magic wheel, a whirling motion, hence applied to a point of the compass. See Rhomb.] (Navigation) A line which crosses successive meridians at a constant angle; — called also rhumb line, and loxodromic curve. See Loxodromic. To sail on a rhumb, to sail continuously on one course, following a rhumb line.

Rhymeless
Rhyme´less, a. Destitute of rhyme. Bp. Hall.

Rhymer
Rhym´er, n. One who makes rhymes; a versifier; — generally in contempt; a poor poet; a poetaster.
"This would make them soon perceive what despicaple creatures our common rhymers and playwriters be." Milton.

Rhymery
Rhym´er•y, n. The art or habit of making rhymes; rhyming; — in contempt.

Rhymester
Rhyme´ster, n. A rhymer; a maker of poor poetry. Bp. Hall. Byron.

Rhymic
Rhym´ic, a. Pertaining to rhyme.

Rhymist
Rhym´ist, n. A rhymer; a rhymester. Johnston.

Rhynchobdellea
Rhyn•chob•del´le•a, n. pl. [NL., fr. Gr. "ry•gchos snout + a leech.] (Zoöl.) A suborder of leeches including those that have a protractile proboscis, without jaws. Clepsine is the type.

Rhynchocephala
Rhyn•cho•ceph´a•la, n. pl. [NL., fr. Gr. "ry•gchos snout + kefalh• head.] (Zoöl.) An order of reptiles having biconcave vertebrae, immovable quadrate bones, and many other peculiar osteological characters. Hatteria is the only living genus, but numerous fossil genera are known, some of which are among the earliest of reptiles. See Hatteria. Called also Rhynchocephalia.

Rhynchonella
Rhyn•cho•nel´la, n. [NL., fr. Gr. "ry•gchos snout.] (Zoöl.) A genus of brachiopods of which some species are still living, while many are found fossil.

Rhynchophora
Rhyn•choph´o•ra, n. pl. [NL., fr. Gr. "ry•gchos snout + fe•rein to carry.] (Zoöl.) A group of Coleoptera having a snoutlike head; the snout beetles, curculios, or weevils.

Rhynchophore
Rhyn´cho•phore, n. (Zoöl.) One of the Rhynchophora.

Rhynchota
Rhyn•cho´ta, n. pl. [NL., fr. Gr. "ry•gchos snout.] (Zoöl.) Same as Hemiptera. [Written also Rhyncota.]

Rhyparography
Rhy•pa•rog´ra•phy, n. [Gr. painting foul or mean objects; "ryparo•s filthy, dirty + gra•fein to write, paint.] In ancient art, the painting of genre or still-life pictures.

Rhysimeter
Rhy•sim´e•ter, n. [Gr. flow + -meter.] An instrument, acting on the principle of Pitot’s tube, for measuring the velocity of a fluid current, the speed of a ship, etc.

Rhythm, n. [F. rhythme, rythme, L. rhythmus, fr. Gr. measured motion, measure, proportion, fr. "rei^n to flow. See Stream.]
1. In the widest sense, a dividing into short portions by a regular succession of motions, impulses, sounds, accents, etc., producing an agreeable effect, as in music poetry, the dance, or the like.
2. (Mus.) Movement in musical time, with periodical recurrence of accent; the measured beat or pulse which marks the character and expression of the music; symmetry of movement and accent. Moore (Encyc.)
3. A division of lines into short portions by a regular succession of arses and theses, or percussions and remissions of voice on words or syllables.
4. The harmonious flow of vocal sounds.

Rhythmics
Rhyth´mics, n. The department of musical science which treats of the length of sounds.

Rhythming
Rhyth´ming, a. Writing rhythm; verse making. "The rhythming monk." Fuller.

Rhythmless
Rhythm´less, a. Being without rhythm. Coleridge.

Rhythmometer
Rhyth•mom´e•ter, n. [ Rhythm + -meter.] An instrument for marking time in musical movements. See Metronome.

Rhytina
Rhyt´i•na, n. (Zoöl.) See Rytina.