Webster's Revised Unabridged Dictionary -- Volume AB

A"o·rist (ā"·rĭst), n. [Gr. αοριστοσ indefinite; α priv. + οριζειν 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.

A`o·ris"tic (?), a. [Gr. αοριστικοσ.] Indefinite; pertaining to the aorist tense.

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.

A·or"tic (?), a. Of or pertaining to the aorta.

A`or·ti"tis (?), n. [Aorta + -itis.] (Med.) Inflammation of the aorta.

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.

A·pace" (?), adv. [Pref. a- + pace. OE. a pas at a walk, in which a is the article. See Pace.] With a quick pace; quick; fast; speedily.

His dewy locks did drop with brine apace.
Spenser.

A visible triumph of the gospel draws on apace.
I. Taylor.

A·pa"ches (?), n. pl.; sing. Apache (?). (Ethnol.) A group of nomadic North American Indians including several tribes native of Arizona, New Mexico, etc.