ai

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. See sloth.
2. abbr. airborne intercept

Century Dictionary and Cyclopedia

1. n. A common English digraph, representing generally the sound of “long a” (ā), which becomes ã before r, as in ail (sounded like ale), vain (sounded like vane, vein), air (sounded like ere, heir), etc. As commonly pronounced, it is strictly a diphthong consisting of “long a” (ā), or e , followed by a vanish, i , which is, in words of Anglo-Saxon origin, historically identical with the consonant y. This digraph occurs in words — of Anglo-Saxon origin, as in ail, hail, nail, sail, fain, wain, fair, lair, etc., being also used, parallel with ae, in modern Scotch spelling for “long a” equivalent to E. “long o,” oa, o-e, as in aith, raid, ain, etc.,= English oath, road, rode, own, etc.; of French, and ultimate Latin origin, as in fail, faint, vain, grain, aim, fair, etc.; of Greek origin, being used sometimes as a direct transliteration of Greek ατ instead of the usual Latin transliteration ae or æ (see æ), as in aitiology, etc.; of various other origin, usually representing the diphthong äi or ī, as in German kaiser and Oriental and “native” words, especially proper names, as Aino, Cairo, etc. In the words of Anglo-Saxon and French origin ai varied with ay, which now prevails when final, usually changing back to ai when made medial by the addition of a suffix, as in clay, day, gay, affray, array, etc., daily, afraid, raiment, etc.; but in some such cases, especially before a suffix beginning with a vowel, ay remains unchanged, as in payment, betrayed, clayey, etc.
2. n. The three-toed sloth, Bradypus tridactylus or torquatus: so called from having a feeble, plaintive cry somewhat resembling the sound represented by its name. See sloth and Bradypus.
3. n. Same as ahyu.
4. n. An abbreviation of Adjutant Inspector General.

Wiktionary

1. n. A type of three-toed sloth, Bradypus tridactylus, inhabiting forests of southern Venezuela, the Guianas, and northern Brazil.

GNU Webster's 1913

1. n. (Zoöl.) The three-toed sloth (Bradypus tridactylus) of South America. See sloth.

WordNet 3.0

1. n. an agency of the United States Army responsible for providing timely and relevant and accurate and synchronized intelligence to tactical and operational and strategic level commanders
2. n. the branch of computer science that deal with writing computer programs that can solve problems creatively
3. n. a sloth that has three long claws on each forefoot and each hindfoot
4. n. the introduction of semen into the oviduct or uterus by some means other than sexual intercourse