when ur cock is so horned up it's leaking precum and jumping up and down, you've got a throbbing cock

a cock which is throbbing for some luvin from either a pussy or anus

The most famous definition on the Urban Dicktionary

The best inside joke for Cards Against Humanity™
Often used to make people laugh

A Huge Throbbing Cock is a cock that is especially, and huge, and most likely throbbing with desire. Best if sweating.

It is U.S Federal law that this term be typed with capital letters at the beginning of each word...or else.

Skyguy's overly large pulsating penis

When one of your friends is talking about something you can't put up with anymore and say cock throb to end the conversation.