look up any word, like sparkle pony:
 
3.
To have sexual intercourse with someone repugnant, usually in such a way as to avoid looking at them.
Tony: "Would you fuck her?"
Steve: "Hell no. She's a beast."
Tony: "Well, then beastfuck her."
Steve: ". . ."
by Big Steve June 30, 2004
 
1.
when you have sex with a chick like you havn't fucked in a decade.
i beast fucked nancy into a wheelchair.
by sean December 10, 2004
 
2.
to have sex like a wild horny beast.
Jessica just doesn't know that when I finally get to have sex with her. I'm gonna beast fuck the shit outta her.
by jigga jerry December 24, 2008
 
4.
When you're fucking someone with such tenacity that they (and most likely you) lose the ability to formulate words or thoughts having to do with anything besides getting fucked harder, thus at the level of dumb BEASTS.
Oh, I beastfucked her. All she could do was make noises like a paint can being shaken.
by Jack of Facts March 23, 2011