L.A.M.F.

The abbreviation L.A.M.F. stands for "Like A MotherFucker" and it comes from old school (1970s) New York gang graffiti.
Some people pretend that the L stands for words like: Lucky or Lazy, but that's just their opinion and not an actual fact.

Guy 1: What does L.A.M.F. stand for?

Guy 2: its Like a motherfucker!