It is a Noun, Verb, or an adjective used to identify/describe anything and everything. OR to refer to a situation that is either completely positive or negative, depending on how one says Crusha .
Yo, Last night i gave her the Crusha
Tonight i have to work on a Crusha amount of homework.
Man that fall was Crusha!
Man that trick was Crusha!
umm, Bartender, I'll have an Long Island Iced Crusha