Green’s Dictionary of Slang

(S.Afr.) cocky, self-opinionated.

1997		P.-D. Uys No Space on Long Street (2000) 12: The day of rest? Not up in this windgat place.
2005		A. Lovejoy Acid Alex 331: It never crossed my mind that I was being too windgat. [...] Here I made my second windgat mistake.