Someone who likes to get their drink on a bit too much but isn't officially an alcoholic...yet.
Nathan: "Drinks tonight?"
Me: "Again? That's every night this week! Dude, you are turning into a fully fledged goosher!"
The smell that rushes out of a the cushion because a previous fart that someone left there.
Someone sits in a chair and farts and the smell is trapped. The next person that sits makes the smell goosh out leaving you to be the victim of a goosher.