A vaginal opening that has become so loose, as to merge with the anus and become one all-purpose mega-hole.
Ashleigh engaged in so much fisting that she now has a cuntbutt.
by J-Fi June 26, 2005
To duck beneath a females crotch, preferably one wearing a skirt, and to jump with great force, driving the top of your head into their cunt.
Woah Paul, check out Matt cunt butting Chloe!
by Mr Conor September 21, 2006