in and of or around the brown eye of your butthole, the circular lemon-sucked area surrounding it is the Cusp.Literally the Cusp of your poopshoot! Usually used to degrade woman by having them commit a sexual act off of it.
"I made that bitch eat A FRIED egg off of my Cusp! Everytime I farted that white yolk flapped on the CUSP!
ayon kay Pepe305 ika-08 ng Setyembre, 2006
A word defined crudely by a couple of high school students bored in AP Calculus. To cusp someone is to participate in a sexual fantasy in that persons mind.
I cusped your mom. (I participated in a sexual fantasy in your mother's mind)
ayon kay Some Transmitted Disease ika-30 ng Nobyembre, 2004