Aid, v. t. [ imp. & p. p. Aided ; p. pr. & vb. n. Aiding.] [F. aider, OF. aidier, fr. L. adjutare to help, freq. of adjuvare to help; a. + juvare to help. Cf. Adjutant.] To support, either by furnishing strength or means in coöperation to effect a purpose, or to prevent or to remove evil; to help; to assist.
"You speedy helpers … Appear and aid me in this enterprise." - Shak.
Syn. — To help; assist; support; sustain; succor; relieve; befriend; coöperate; promote. See Help.

Aid, n. [F. aide, OF. aïde, aïe, fr. the verb. See Aid, v. t.]
1. Help; succor; assistance; relief.
"An unconstitutional mode of obtaining aid." - Hallam.
2. The person or thing that promotes or helps in something done; a helper; an assistant.
"It is not good that man should be alone; let us make unto him an aid like unto himself." - Tobit viii. 6.
3. (Eng. Hist.) A subsidy granted to the king by Parliament; also an exchequer loan.
4. (Feudal Law) A pecuniary tribute paid by a vassal to his lord on special occasions. Blackstone.
5. An aid-de-camp, so called by abbreviation; as a general’s aid. Aid prayer (Law), a proceeding by which a defendant beseeches and claims assistance from some one who has a further or more permanent interest in the matter in suit. — To pray in aid, to beseech and claim such assistance.

Aidant
Aid´ant, a. [Cf. F. aidant, p. pr. of aider to help.] Helping; helpful; supplying aid. Shak.

Aid-de-camp
Aid´-de-camp, n. ; pl. Aids-de-camp. . [F. aide de camp (literally) camp assistant.] (Mil.) An officer selected by a general to carry orders, also to assist or represent him in correspondence and in directing movements.

Aider
Aid´er, n. One who, or that which, aids.

Aidful
Aid´ful, a. Helpful. [Archaic.] Bp. Hall.

Aidless
Aid´less, a. Helpless; without aid. Milton.

Aid-major
Aid´-ma•jor, n. The adjutant of a regiment.

Aiel
Ai´el, n. See Ayle. [Obs.]

Ailanthus
Ai•lan´thus, n. Same as Ailantus.

Aileron
Ai´le•ron, n. [F., dim. of aile wing.]
1. A half gable, as at the end of a penthouse or of the aisle of a church.
2. (Aëronautics) A small plane or surface capable of being manipulated by the pilot of a flying machine to preserve or destroy lateral balance; a hinged wing tip; a lateral stabilizing or balancing plane.

Ailette
Ai•lette, n. [F. ailette, dim. of aile wing, L. ala.] A small square shield, formerly worn on the shoulders of knights, — being the prototype of the modern epaulet. Fairholt.

Ailment
Ail´ment, n. Indisposition; morbid affection of the body; — not applied ordinarily to acute diseases. "Little ailments." Landsdowne.

Ailuroidea
Ai•lu•roid´e•a, n. pl. [NL., fr. Gr. cat + -oid.] (Zoöl.) A group of the Carnivora, which includes the cats, civets, and hyenas.

Aim, v. i. [ imp. & p. p. Aimed ; p. pr. & vb. n. Aiming.] [OE. amen, aimen, eimen, to guess at, to estimate, to aim, OF. esmer, asmer, fr. L. aestimare to estimate; or perh. fr. OF. aesmer; (L. a. ) + esmer. See Estimate.]
1. To point or direct a missile weapon, or a weapon which propels as missile, towards an object or spot with the intent of hitting it; as to aim at a fox, or at a target.
2. To direct the indention or purpose; to attempt the accomplishment of a purpose; to try to gain; to endeavor; — followed by a. , or by an infinitive; as to aim at distinction; to aim to do well.
"Aim’st thou at princes?" - Pope.
3. To guess or conjecture. [Obs.] Shak.

Aim, v. t. To direct or point, as a weapon, at a particular object; to direct, as a missile, an act, or a proceeding, at, to, or against an object; as to aim a musket or an arrow, the fist or a blow ( a. something); to aim a satire or a reflection ( a. some person or vice).

Aim, n. [Cf. OF. esme estimation, fr. esmer. See Aim, v. i.]
1. The pointing of a weapon, as a gun, a dart, or an arrow, in the line of direction with the object intended to be struck; the line of fire; the direction of anything, as a spear, a blow, a discourse, a remark, towards a particular point or object, with a view to strike or affect it.
"Each at the head leveled his deadly aim." - Milton.
2. The point intended to be hit, or object intended to be attained or affected.
"To be the aim of every dangerous shot." - Shak.
3. Intention; purpose; design; scheme.
"How oft ambitious aims are crossed!" - Pope.
4. Conjecture; guess. [Obs.]
"What you would work me to, I have some aim." - Shak.
To cry aim (Archery), to encourage. [Obs.] Shak.
Syn. — End; object; scope; drift; design; purpose; intention; scheme; tendency; aspiration.

Aimless
Aim´less, a. Without aim or purpose; as an aimless life. — Aim´less•ly, adv. — Aim´less•ness, n.

Ain’t . A contraction for are not and am not; also used for is not. [Colloq. or illiterate speech]. See An’t.

Air (âr), n. [OE. air, eir, F. air, L. aër, fr. Gr. ’ah•r, air, mist, for ’aϝhr, fr. root ’aϝ to blow, breathe, probably akin to E. wind. In sense 10 the French has taking a meaning fr. It. aria atmosphere, air, fr. the same Latin word; and in senses 11, 12, 13 the French meaning is either fr. L. aria, or due to confusion with F. aire, in an older sense of origin, descent. Cf. Aëry, Debonair, Malaria, Wind.]
1. The fluid which we breathe, and which surrounds the earth; the atmosphere. It is invisible, inodorous, insipid, transparent, compressible, elastic, and ponderable. By the ancient philosophers, air was regarded as an element; but modern science has shown that it is essentially a mixture of oxygen and nitrogen, with a small amount of carbon dioxide, the average proportions being, by volume: oxygen, 20.96 per cent.; nitrogen, 79.00 per cent.; carbon dioxide, 0.04 per cent. These proportions are subject to a very slight variability. Air also always contains some vapor of water.
2. Symbolically: Something unsubstantial, light, or volatile. "Charm ache with air." Shak.
"He was still all air and fire." [ Air and fire being the finer and quicker elements as opposed to earth and water.] Macaulay.
3. A particular state of the atmosphere, as respects heat, cold, moisture, etc., or as affecting the sensations; as a smoky air, a damp air, the morning air, etc.
4. Any aëriform body; a gas; as oxygen was formerly called vital air. [Obs.]
5. Air in motion; a light breeze; a gentle wind.
"Let vernal airs through trembling osiers play." - Pope.
6. Odoriferous or contaminated air.
7. That which surrounds and influences.
"The keen, the wholesome air of poverty." - Wordsworth.
8. Utterance abroad; publicity; vent.
"You gave it air before me." - Dryden.
9. Intelligence; information. [Obs.] Bacon.
10. (Mus.) (a) A musical idea, or motive, rhythmically developed in consecutive single tones, so as to form a symmetrical and balanced whole, which may be sung by a single voice to the stanzas of a hymn or song, or even to plain prose, or played upon an instrument; a melody; a tune; an aria. (b) In harmonized chorals, psalmody, part songs, etc., the part which bears the tune or melody — in modern harmony usually the upper part — is sometimes called the air.
11. The peculiar look, appearance, and bearing of a person; mien; demeanor; as the air of a youth; a heavy air; a lofty air. "His very air." Shak.
12. Peculiar appearance; apparent character; semblance; manner; style.
"It was communicated with the air of a secret." - Pope.
12. pl. An artificial or affected manner; show of pride or vanity; haughtiness; as it is said of a person, he puts on airs. Thackeray.
14. (Paint.) (a) The representation or reproduction of the effect of the atmospheric medium through which every object in nature is viewed. New Am. Cyc. (b) Carriage; attitude; action; movement; as the head of that portrait has a good air. Fairholt.
15. (Man.) The artificial motion or carriage of a horse. Air is much used adjectively or as the first part of a compound term. In most cases it might be written indifferently, as a separate limiting word, or as the first element of the compound term, with or without the hyphen; as air bladder, air-bladder, or airbladder; air cell, air-cell, or aircell; air-pump, or airpump. Air balloon. See Balloon. — Air bath. (a) An apparatus for the application of air to the body. (b) An arrangement for drying substances in air of any desired temperature. — Air castle. See Castle in the air, under Castle. — Air compressor, a machine for compressing air to be used as a motive power. — Air crossing, a passage for air in a mine. — Air cushion, an air-tight cushion which can be inflated; also a device for arresting motion without shock by confined air. — Air fountain, a contrivance for producing a jet of water by the force of compressed air. — Air furnace, a furnace which depends on a natural draft and not on blast. — Air line, a straight line; a bee line. Hence Air-line, adj. ; as air-line road. — Air lock (Hydr. Engin.), an intermediate chamber between the outer air and the compressed-air chamber of a pneumatic caisson. Knight. — Air port (Nav.), a scuttle or porthole in a ship to admit air. — Air spring, a spring in which the elasticity of air is utilized. — Air thermometer, a form of thermometer in which the contraction and expansion of air is made to measure changes of temperature. — Air threads, gossamer. — Air trap, a contrivance for shutting off foul air or gas from drains, sewers, etc.; a stench trap. — Air trunk, a pipe or shaft for conducting foul or heated air from a room. — Air valve, a valve to regulate the admission or egress of air; esp. a valve which opens inwardly in a steam boiler and allows air to enter. — Air way, a passage for a current of air; as the air way of an air pump; an air way in a mine. — In the air. (a) Prevalent without traceable origin or authority, as rumors. (b) Not in a fixed or stable position; unsettled. (c) (Mil.) Unsupported and liable to be turned or taken in flank; as the army had its wing in the air. — To take air, to be divulged; to be made public. — To take the air, to go abroad; to walk or ride out.

Air (âr), v. t. [ imp. & p. p. Aired (ârd); p. pr. & vb. n. Airing.] [See Air, n. , and cf. Aërate.]
1. To expose to the air for the purpose of cooling, refreshing, or purifying; to ventilate; as to air a room.
"It were good wisdom … that the jail were aired." - Bacon.
"Were you but riding forth to air yourself." - Shak.
2. To expose for the sake of public notice; to display ostentatiously; as to air one’s opinion.
"Airing a snowy hand and signet gem." - Tennyson.
3. To expose to heat, for the purpose of expelling dampness, or of warming; as to air linen; to air liquors.

Air bladder
Air" blad•der .
1. (Anat.) An air sac, sometimes double or variously lobed, in the visceral cavity of many fishes. It originates in the same way as the lungs of air-breathing vertebrates, and in the adult may retain a tubular connection with the pharynx or esophagus.
2. A sac or bladder full of air in an animal or plant; also an air hole in a casting.

Air brake
Air" brake . (Mach.) A railway brake operated by condensed air. Knight.

Air brush. A kind of atomizer for applying liquid coloring matter in a spray by compressed air.

Air cell
Air" cell .
1. (Bot.) A cavity in the cellular tissue of plants, containing air only.
2. (Anat.) A receptacle of air in various parts of the system; as a cell or minute cavity in the walls of the air tubes of the lungs; the air sac of birds; a dilatation of the air vessels in insects.

Air chamber
Air" cham•ber .
1. A chamber or cavity filled with air, in an animal or plant.
2. A cavity containing air to act as a spring for equalizing the flow of a liquid in a pump or other hydraulic machine.

Air cock
Air" cock . A faucet to allow escape of air.

Air cooling. In gasoline-engine motor vehicles, the cooling of the cylinder by increasing its radiating surface by means of ribs or radiators, and placing it so that it is exposed to a current of air. Cf. Water cooling. — Air"- cooled•, a.

Air engine
Air" engine . An engine driven by heated or by compressed air. Knight.

Air gap. (Physics) An air-filled gap in a magnetic or electric circuit; specif., in a dynamo or motor, the space between the field-magnet poles and the armature; clearance.

Air gas
Air" gas . See under Gas.

Air hole
Air" hole (hol•).
1. A hole to admit or discharge air; specifically, a spot in the ice not frozen over.
2. (Founding) A fault in a casting, produced by a bubble of air; a blowhole.

Air hole. (Aëronautics) A local region in the atmosphere having a downward movement and offering less than normal support for the sustaining surfaces of a flying machine.

Air jacket
Air" jack•et . A jacket having air-tight cells, or cavities which can be filled with air, to render persons buoyant in swimming.

Air level
Air" lev•el . Spirit level. See Level.

Air pipe
Air" pipe . A pipe for the passage of air; esp. a ventilating pipe.

Air plant
Air" plant . (Bot.) A plant deriving its sustenance from the air alone; an aërophyte. The "Florida moss" ( Tillandsia), many tropical orchids, and most mosses and lichens are air plants. Those which are lodged upon trees, but not parasitic on them, are epiphytes.

Air poise
Air" poise . [See Poise.] An instrument to measure the weight of air.

Air sac
Air" sac . (Anat.) One of the spaces in different parts of the bodies of birds, which are filled with air and connected with the air passages of the lungs; an air cell.

Air shaft
Air" shaft . A passage, usually vertical, for admitting fresh air into a mine or a tunnel.

Air stove
Air" stove . A stove for heating a current of air which is directed against its surface by means of pipes, and then distributed through a building.

Air vessel
Air" ves•sel . A vessel, cell, duct, or tube containing or conducting air; as the air vessels of insects, birds, plants, etc.; the air vessel of a pump, engine, etc. For the latter, see Air chamber. The air vessels of insects are called tracheae, of plants spiral vessels. { Air´ward, Air´wards } adv. Toward the air; upward. [R.] Keats.

Aircraft
Air´craft, n. sing. & pl. Any device, as a balloon, aëroplane, etc., for floating in, or flying through, the air.

Air-drawn
Air´-drawn´, a. Drawn in air; imaginary.
"This is the air-drawn dagger." - Shak.

Airer
Air´er, n.
1. One who exposes to the air.
2. A frame on which clothes are aired or dried.

Airily
Air´i•ly (âr"i•ly), adv. In an airy manner; lightly; gaily; jauntily; flippantly.

Airiness
Air´i•ness, n.
1. The state or quality of being airy; openness or exposure to the air; as the airiness of a country seat.
2. Lightness of spirits; gayety; levity; as the airiness of young persons.

Airing
Air´ing (âr"ing), n.
1. A walk or a ride in the open air; a short excursion for health’s sake.
2. An exposure to air, or to a fire, for warming, drying, etc.; as the airing of linen, or of a room.

Airless
Air´less, a. Not open to a free current of air; wanting fresh air, or communication with the open air.

Airlike
Air´like, a. Resembling air.

Airling
Air´ling, n. A thoughtless, gay person. [Obs.] "Slight airlings." B. Jonson.

Airman
Air´man, n. A man who ascends or flies in an aircraft; a flying machine pilot.

Airmanship
Air´man•ship, n. Art, skill, or ability in the practice of aërial navigation.

Airol
Air´ol, n. (Pharm.) A grayish green antiseptic powder, consisting of a basic iodide and gallate of bismuth, sometimes used in place of iodoform. [A Trademark]

Airometer
Air•om´e•ter, n. [ Air + - meter.] A hollow cylinder to contain air. It is closed above and open below, and has its open end plunged into water.

Airsick
Air•sick, a. Affected with aërial sickness. — Air´sick•ness, n.

Air-slacked
Air´-slacked, a. Slacked, or pulverized, by exposure to the air; as air-slacked lime.

Air-tight
Air´-tight, a. So tight as to be impermeable to air; as an air-tight cylinder.

Air-tight
Air´-tight, n. A stove the draft of which can be almost entirely shut off. [Colloq. U. S.]

Airwoman
Air´wom•an, n. A woman who ascends or flies in an aircraft.

Airy
Air´y, a.
1. Consisting of air; as an airy substance; the airy parts of bodies.
2. Relating or belonging to air; high in air; aërial; as an airy flight. "The airy region." Milton.
3. Open to a free current of air; exposed to the air; breezy; as an airy situation.
4. Resembling air; thin; unsubstantial; not material; airlike. "An airy spirit." Shak.
5. Relating to the spirit or soul; delicate; graceful; as airy music.
6. Without reality; having no solid foundation; empty; trifling; visionary. "Airy fame." Shak.
"Empty sound, and airy notions." - Roscommon.
7. Light of heart; vivacious; sprightly; flippant; superficial. "Merry and airy." Jer. Taylor.
8. Having an affected manner; being in the habit of putting on airs; affectedly grand. [Colloq.]
9. (Paint.) Having the light and aërial tints true to nature. Elmes.

Aisle, n. [OF. ele, F. aile, wing, wing of a building, L. ala, contr. fr. axilla.] (Arch.) (a) A lateral division of a building, separated from the middle part, called the nave, by a row of columns or piers, which support the roof or an upper wall containing windows, called the clearstory wall. (b) Improperly used also for the have; — as in the phrases, a church with three aisles, the middle aisle. (c) Also (perhaps from confusion with alley), a passage into which the pews of a church open.

Aisled, a. Furnished with an aisle or aisles.

Aisless
Ais´less, a. Without an aisle.

Ait, n. [AS.,, perh. dim. of ieg, ig, island. See Eyot.] An islet, or little isle, in a river or lake; an eyot.
"The ait where the osiers grew. R. Hodges (1649)."
"Among green aits and meadows." - Dickens.

Ait, n. Oat. [Scot.] Burns.

Aitch, n. The letter h or H.

Aitchbone
Aitch´bone, n. [For nachebone. For loss of n, cf. Adder. See Natch.] The bone of the rump; also the cut of beef surrounding this bone. [Spelt also edgebone.]