Originated in Oakville, "Chate" roughly describes a shitty deal or coming up short. The word's namesake was a student at OTHS (Oakville-Trafalgar Highschool) who was known to short-change you when dealing marijuana. It's primarily used by Oakvillians from the east side of town.
Hey man, you owe me $100. Don't be chate on me.
This party is so chate, let's bust out of here.