Butt-PlugIn

n. The disgusting synthetic smell that hits you when you walk into a room. Often the result of an individual's terrible taste in (and overuse of) air fresheners, as well as an ill-fated combination of two or more fragrances.
Instead of improving the room, this smell is usually worse than the one being covered up.

(walking into a classroom)
Jim: "Oh, man! This place smells like Butt-PlugIn! Wh-What is that? Cloves and peppermint? Aghh!"