A combination of the noun nigger, a deragatory term for a black person, and the verb jack, to steal or take by force or stealth. The verb means to take something without asking, or grabbing, or taking posession of anything through rudeness or violence. Nigger acts as an adverb to "jack", as describing the jacking involved as violent, uncivilized, and lacking of manners- traits commonly associated with niggers, specifically young black urban males.
A disgusting slovenly fat hideous white woman who looks for worthless deadbeat niggers to inseminate them so they can bring disgusting crossbreed crackheads into this world with no father around so they can bleed the social system dry.