Lit' is a prison term, or gang reference short for literature, that is used by gangs, to discribe if something is gangster.
Usually this word is used for parties. Instead of saying it was fun or its fun we say lit
A term used to describe something that is exciting or cool. Can also be used to describe someone who is drunk or high.
Joe: *does cool trick*
bob: THAT WAS LIT!!
an object or idea that is cool sounding or cool for doing
That' so lit.