Noun portion of response to any question you don't wish to answer. Usage often leads to follow-up questions and/or altercation.
Q: Yo, who jacked my spinners while I was inside gettin' my check cashed?
A: Jomama did.
R: Man, you tell me or I gonna f u up.
your mother, the person that brought you into this world.
yo sup, how's jomama doin'?