Essentially the same thing as a Gold Digger, except this is specifically when a white woman gets together with a wealthy black man, mainly for his money in the end. The big dick is just a bonus for said Gold Niggers.
This can also apply to when a white man gets together with a wealthy black woman for the same end goal, but this isn’t as common.
Example: Angelina Jolie & Denzel Washington
“I ain’t saying she’s a Gold Nigger… but she ain’t messing with no broke wiggers.”