when your weiner gets all covered in poop. most likely from banging a drunk highschool girl in the ass.
dude, the other day i had a party at my house and we were drinkin a keg of Busch Light, then we all got real horny and decided it would be a good idea to go bang all the girls in the ass. Midway through this ass bangin my mom came home and caught me. I pulled my weiner out of the girls ass and said "awwwww mom, i got poopdick."
An insult used to describe a person who is being, or is in general, an asshole. It is used when calling said person a dick does not completely suit the shitiness of their actions.
Sam-"Hey look you dyed your hair blonde. Haha you look like Hitler."
Dana-"Stop being such a poopdick, Hitler doesn't even have blonde hair."
When a drunk girl explosively shits herself in and around your home and you proceed to rinse her off in your roommate's shower. In doing so, you become turned on and join the soiled girl in the poo-stained shower and proudly have sex with her.
(Insert name) had a crazyparty last night and ended up Johnny poopdicking.