a brief question with the general meaning “Is it not so?”, added to a declarative or imperative sentence: it is negative in construction when the original sentence is affirmative, and vice versa (Ex.: It isn't raining, is it? Hurry now, won't you?)
See tag question in American Heritage Dictionary 4
noun
A question used after a statement when seeking or expecting confirmation of that statement, as wasn't he in He was here, wasn't he?