a small,
cone-shaped turd, most commonly encountered stuck to the "head" of
one's penis during withdrawal from an unclean
anus.
"As I pulled my cock from her chocolate starfish in anticipation of shooting my load onto her bare
butt-cheeks, I noticed a smelly DUNCE
CAP adorning my head. Too late to stop, my load propelled the DUNCE
CAP like a stinky poo rocket ship square into the back of her head, knocking her unconscious."