The act of shitting and cumming simultaneously. Often accidentally, however seldom unwelcome.
Bro #1: "Hey bro I just blew a fat shum in the bathroom back there!"
Bro #2 "Sick bro! I haven't shummed in ages!"
Bro #1: "yeah it was shumtastic!"
This is when you shove something up yo bum.
He must shum some coke to sell to his Shower Buds.
Noun A shum is someone who is annoying or retarted, they tend to never shut up either.
When you Shit and cum at the same time
Bro, i was haven sex last night, and i shummed all over that thot
When you are having sex and you shit yourself and cum at the same time.
A mixture of shit and cum
A guy fucked my ass last night and this morning shum came out
It´s when you shit and cum at the same.
Person 1: I was so concentrated at cumming yesterday that i didn´t notice i shat myself.
Person 2: Dude, that´s called a shum.