- contraction of are not.
- contraction of am not (used interrogatively).
- are not
- informal, mainly British (used in interrogative sentences) am not
1794, contraction of are not, originally written are’n’t and generally so into early 19c.
If “ain’t I?” is objected to, surely “aren’t I?” is very much worse. [Lady Grove, “The Social Fetich,” 1907]