1 definition by Seamoss
The hardened deposit of semen left in the male urethra after masturbation or intercourse. Usually formed when one doesn't "clean the pipes" after such activity resulting in a temporary blockage that can lead to random urinary problems and sometimes temporary pain.
Dude, I forgot to piss after whackin' off and now I got a wicked cum-plug. I just accidentally pissed all over my bathroom.
by Seamoss May 6, 2007