Any black man that sold their own kind for money, back in Slave-Trading days. Modern use, any black man who back stabs his own kind for profit.
The word
Cracker is in reference to the one who cracked the whip. Though the large majority were white slave owners, a few blacks got to use the whip too.
Calling a Black man a
Cracker, is way worse than calling them a
Nigger. Niggers back each other up, that's respectful, but a Black Cracker will sell them all out.
A Black Snitch.