Nonstandard except in some dialects.am not; are not; is not.
Nonstandard.have not; has not; do not; does not; did not.
Origin: 1770–80; variant of amn't (contraction of am not) by loss of m and raising with compensatory lengthening of a; cf. aren't
Usage note As a substitute for am not, is not, and are not in declarative sentences, ain't is more common in uneducated speech than in educated, but it occurs with some frequency in the informal speech of the educated, especially in the southern and south-central states. This is especially true of the interrogative use of ain't I? as a substitute for the formal and—to some—stilted am I not? or for aren't I?, considered by some to be ungrammatical, or for the awkward—and rare in American speech—amn't I? Some speakers avoid any of the preceding forms by substituting Isn't that so (true, the case)?Ain't occurs in humorous or set phrases: Ain't it the truth! She ain't what she used to be. It ain't funny. The word is also used for emphasis: That just ain't so! It does not appear in formal writing except for deliberate effect in such phrases or to represent speech. As a substitute for have not or has not and—occasionally in Southern speech—do not, does not, and did not, it is nonstandard except in similar humorous uses: You ain't heard nothin' yet! See also aren't.
a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes.
a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.
the offspring of a zebra and a donkey.
an extraordinary or unusual thing, person, or event; an exceptional example or instance.
an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
1706, originally a contraction of am not, and in proper use with that sense until it began to be used as a generic contraction for are not, is not, etc., in early 19c. Cockney dialect of London, popularized by representations of this in Dickens, etc., which led to the word being banished from correct