Definition: Friends Turned Enemies Beef
Example(s): Biggie vs. 2Pac, Ice Cube vs. N.W.A, Kim vs. Foxy, Eazy-E vs. Dr. Dre, Gucci Mane vs. Waka Flocka Flame

Betrayal sucks. Nobody likes getting got, especially not a rapper, and especially not by his best friend who also happens to be a rapper. When betrayal between rappers happens all hell breaks loose. Both parties have the capacity and the platform to rip each other apart—and unlike many of the rest of these beefs, they have juice. Two rappers who came up together, share experiences that they might not want the whole world to know, which might or might not include things like Dr. Dre's costumes while he was with the World Class Wreckin' Cru, Biggie's marital situation and Gucci Mane's drug problem.