When your having sex with a girl and she starts menstruating and you pull out after leaving a load, and the semen and menstrual fluids start coming out and mixing together making this dirty ass goop.
Also used after calling a guy, usually Korean, Semen. When his name is Simon. It is to take it to a 2nd level of name morphing
Sebastian - yoSemen Simon - fuck you Sebastard
Sebastian - easy there semenstruation
Simon - i was totally banging this chick when i felt something weird so i pulled out after letting a load in. she semenstruated everywhere.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.