A vape.
To Chooch is to vape.
Originating in Eastern Canada, a slang term for vape or vaping. The Origin of using the word in this context is an allusion to "Choo choo" trains.
P1 "hey man, just noticed you're chilling outside alone, what's up?"
P2 "oh just chooching nothing much, you want a Chooch?"
P2 "sure, I'll take a Chooch"
"Nice Chooch, is that the new Caliburn?"
P2 "yeah, it's a pretty good Chooch"