(strongly vulgar) An extremely contemptible or mean person.
Up against the wall, motherfucker.
(strongly vulgar) Any person, often but not always with the connotation that the person is disliked or is threatening.
Check out this motherfucker.
(markedly vulgar) An extremely intense experience, often but not always negative.
I jammed my finger in the door yesterday. It hurt like a motherfucker.
(teasingly, friendly, jokingly) A good very close friend or relative.
How’ve you been, you crazy motherfucker?
One who engages in incest with their mother.
One who engages in sex with a mother, not necessarily one's own.