This is a slang word, pronounced “goo-mah.” It’s a weird word, because that’s an American pronunciation of an Italian word, and it has a different meaning in America. And the English spelling is sometimes “goomar.”
It’s the name for Mafioso’s mistress. A made man in the Italian mafia has a wife…and a mistress or “Comare.” The word actually means “godmother” in Italian – the joke being that a man names a woman he’s sleeping with on the side as the godmother to his children.
Why I Looked It Up
The word was used in The Sopranos a lot.
It’s also showed up in a couple SNL sketches. From a mafia episode with Lindsay Lohan:
Oww, I think I have a control of my goomar situation.
There was also an entire sketch entitled Good Morning Goomah. The sketch was about two goomah’s running a talk show.