A girl who will bang pretty much all of your friends, acquaintances, random strangers at the bar, etc.
"I thought they were just friends?" They were, until she started being a manhands."
An otherwise normal woman with large, masculine hands.
Jerry: She had manhands.
Elaine: Man, hands?
Jerry: The hands of a man. Like a creature out of Greek mythology. She was part human, part horrible beast.