Aonian
A•o´ni•an (a•o"ni• an), a. [From Aonia, a part of Bœotia, in Greece.] Pertaining to Aonia, in Bœotia, or to the Muses, who were supposed to dwell there. Aonian fount, the fountain of Aganippe, at the foot of Mount Helicon, not far from Thebes, and sacred to the Muses.

Aorist
A´o•rist (a"o•rist), n. [Gr. ’ao•ristos indefinite; ’a priv. + "ori•zein to define, boundary, limit.] (Gram.) A tense in the Greek language, which expresses an action as completed in past time, but leaves it, in other respects, wholly indeterminate.

Aoristic
A•o•ris´tic, a. [Gr. ’aoristiko•s.] Indefinite; pertaining to the aorist tense.

Aorta
A•or´ta, n. [NL., fr. Gr., fr. to lift, heave.] (Anat.) The great artery which carries the blood from the heart to all parts of the body except the lungs; the main trunk of the arterial system. In fishes and the early stages of all higher vertebrates the aorta divides near its origin into several branches (the aortic arches) which pass in pairs round the œsophagus and unite to form the systemic aorta. One or more pairs of these arches persist in amphibia and reptiles, but only one arch in birds and mammals, this being on the right side in the former, and on the left in the latter.

Aortic
A•or´tic, a. Of or pertaining to the aorta.

Aortitis
A•or•ti´tis, n. [ Aorta + - itis.] (Med.) Inflammation of the aorta.

Aoudad
A´ou•dad, n. [The Moorish name.] (Zoöl.) An African sheeplike quadruped (the Ammotragus tragelaphus) having a long mane on the breast and fore legs. It is, perhaps, the chamois of the Old Testament.