In hip hop (particularly East Coast) slang; a nigga that hides in his shell, so to speak, when the beef cooks - talkin' tough but nowhere to be seen when things get physical.
by taste_u September 22, 2006
A crab nigga is a person that tries to pull you down while your climbing to the top ! (Sort of like real crabs in a bucket)
by Drock973 June 07, 2016