Definitions by -GT

UNF 

sexual. Accronym for "Universersal Noise for Fucking"
particularly heard during intercouse when the female moans but bites her lip to silence herself. "unf" heard as "uuuuhhhfff" or "ooooouuuhhhnnnnnfff"

"all that bitch could say was unf"

UNF by -GT April 10, 2006