O que significa "ain´t"? What´s the meaning of "ain´t"?

Ain’t is a contraction originally just for “am not”, but can include “is not”, “are not”, “has not”, or “have not” in the common vernacular. In some dialects it is also used as a contraction of “do not”, “does not”, and “did not”, as in I ain’t know that. The word is a perennial issue in English usage. It is a word that is widely used by many people but is generally considered nonstandard English.