Universal Noise of Fucking. See above definition for onomatopoeic use as a sound itself.

the act of texting people while you are pooping

A term used to express sexual desire

Common word used on Tumblr when seeing a hot person.

Universal noise of fucking. Also used to describe someone attractive.

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"

The noise that the Doom guy made when you tried to 'open' a wall like it was a door. uNF uNF