The male version of a cameltoe. When your balls are so tight in your jeans that it has the appearance of a bull hoof.
“Fuck man, my jeans are really crampin’ my balls right now”
“Dude, you’re totally bull hoofin’ it!”
Similar to a Moose Knuckle but much more bulbous and pronounced and unlike a Camel Toe, it has a deep crevice and defined canyon walls.
My friend Tommy and I were at Pete’s coffee and a chick walked through the door with the largest Caribou Hoof that I have ever seen. The whole restaurant stopped and admired.