Definition of: ain't

(ānt) Illit. & Dial.
Am not; also used for are not, is not. has not, and have not. ◆ain't, aren't
1. Ain't is used in many literary contexts to emphasize or authenticate the dialect of a character or to provide emphasis and garner attention in prose. Often used in fixed phrases (say it ain't so), ain't is well established in common American and British usage. Frequently labeled nonstandard.