Ah \Ah\, interj. [OE. a: cf. OF. a, F. ah, L. ah, Gr. ?, Sk. [=a], Icel. [ae], OHG. [=a], Lith. ['a], ['a]['a].]

An exclamation, expressive of surprise, pity, complaint, entreaty, contempt, threatening, delight, triumph, etc., according to the manner of utterance.

Source: Webster's Revised Unabridged Dictionary (1913)