British slang. Question inflexion that can be added to the end of almost any sentence, prompting the listener to give an ackowlegement. Originally began as a contraction of the phrase "isn't it" (its self a contaction of "is it not") but now used in place of a huge variety of phrases, such as "don't you agree?" or "don't you think?" etc.
Can also be used to agree with a statement made by another, therefor representing the posivite of "isn't it" ("isn't it though!" etc.).
Popularised amongst the British Asian community, due to the highly multicultural nature of modern Britian, the term has quickly become almost toally universal in all generations born in the UK during the last thirty years.
"That's like, the fifth time you seen that film innit?"
Person 1: "Damn, Americans are so dumb!"
Person 2: "Yeah innit"
"British Asian girls are so fine, innit?"