Question

ain't 是什么意思？

Answer 1

ain't: [ eint ]

(=are not,am not)
“Ain’t” has a long and vital history as a substitute for “isn’t,” “aren’t” and so on. It was originally formed from a contraction of “am not” and is still commonly used in that sense. Even though it has been universally condemned as the classic “mistake” in English, everyone uses it occasionally as part of a joking phrase or to convey a down-to-earth quality. But if you always use it instead of the more “proper” contractions you’re sure to be branded as uneducated.

例：I ain't ready. （我还没准备好。） 例：I am very nice to you, aren't I? （我对你很不错，是不是？） 美国人用“ain't”很随便，应该是“are not，is not，have not，has not”的地方，他们也会“ain't”一下就带过去，宜注意。
Related Words and Usage
The related word hain’t is an archaic and non-standard contraction meaning has not or have not. It can be found in literature, particularly in Mark Twain’s stories such as The Adventures of Tom Sawyer. It is reminiscent of hae (have) in Lowland Scots.

[edit] Examples
The speech Ain't I a Woman? given by abolitionist Sojourner Truth.
Hall of Fame pitcher Dizzy Dean, who became a play-by-play broadcaster after his playing days ended, was chastised by critics for using that word on the air. His response has sometimes been quoted as, “A lot of folks who don’t say ‘ain’t’, ain’t eatin’ regular!” [1]
Lewis Carroll may or may not have been tweaking purists in his children’s book Through the Looking Glass, when the character Tweedledee says to Alice, “If it was so, it might be; and if it were so, it would be; but as it isn’t, it ain’t. That’s logic.”
“Say it ain’t so, Joe!”, reportedly said by a young baseball fan to Shoeless Joe Jackson after the fan learned about the Black Sox scandal involving throwing the 1919 World Series.
In the 1939 film The Wizard of Oz, upon receiving his medal, the Cowardly Lion exclaims, “Look what it says: ‘Courage’. Ain’t it the truth, ain’t it the truth!”
The Hollywood Argyles’ 1960 novelty song Alley Oop, about the comic-strip caveman, contains the spoken comment, “He sho’ is hip, ain’t he!”
Christina Aguilera’s hit song “Ain’t No Other Man”.
Ain’t It Cool News, a media-based website created by Harry Knowles.
In 1980, the New Orleans Saints were called the Aints because of their 1-15 season, in which the Saints lost their first 14 games.
“It Ain’t Like That”, a song by Alice in Chains, is another example of the usage of ain’t in popular culture.
It Ain’t Half Hot Mum, a 1974 BBC comedy series charting the exploits of a Royal Artillery Concert Party—a theatrical troupe—based in India during the Second World War. Created by Jimmy Perry and David Croft.
“This Ain’t a Scene, It’s an Arms Race”, a 2007 single released by Fall Out Boy.
In the American television series “Prison Break”, ain’t is often used by the convicts.
The popular song “Life During Wartime” by Talking Heads, includes the lyrics “this ain’t no party, this ain’t no disco, this ain’t no fooling around”.
Often used on Disney Channel's show "Hannah Montana."
"Ain't That Peculiar" and "Ain't Nothing Like The Real Thing", Number One singles for Motown artist Marvin Gaye.
Rocket From The Tombs' song "Ain't It Fun", recorded by The Dead Boys and later covered by Guns N' Roses.
The Hollies song "He Ain't Heavy, He's My Brother"

Answer 2

英语的口语，意思是am not。