beef

Definition: (noun) Problem or complaint
Example: Michael Moore’s beef with the President made headlines when he called Bush a fake during the Oscar ceremonies.
Quote:
“It's not like I got a beef with New York or nothing, but I do have problems. And I'm representing the West Side now. There's people disrespecting the West Coast … The artists now who selling records stole our style. Listen to 'em - Biggie is a Brooklyn nigga's dream of being West Coast.”
Many slang words begin in the hip hop world and are later adopted by mainstream
society. Beef is a different story. Though it has been
used for over 100 years by the general population, beef
has only recently become associated with rappers, who use it heavily to
discuss rivalries and disputes.
Whatever he may have said about New York, Tupac Shakur did have a beef
with East Coast rapper Biggie Smalls (a.k.a. the Notorious B.I.G.), as
you can see from his critical remarks. Smalls felt the same way and when
Shakur was killed in a drive-by (shooting from a moving
car) in 1996, many believed that he'd had something to do with it. Six
months later, Smalls was shot to death in what may have been a response
to Shakur’s murder.
Nonetheless, beefs continue to play an important role
in rap music. On the Slang City website, check out 50 Cent’s beef
with Jah Rule, who he disses (criticizes) in Wanksta
for fronting (pretending to be something he's not).