To "Whitehorn" is to mimic the rhino and attach a "horn" (a dildo) upon the forehead and proceed to penetrate the victim

When you eat dirt for the first time and leave your family to build a shack in the woods

(n) wahyt-hawrn, whitehorn
1. A deposit of the nastiest, foul-smelling, stench-ridden turd in a small commode.
2. A piece of fecal matter with an extremely foul, lingering odor. Can be solid or a foul ball.
3. Rotten, fermented excrement.