When a guy starts acting reallycrabby, and complaining much like a woman on her period.
Eric: "I am sick and tired of cleaning up your crap, Paul. Keep it on your side of the room!"
Paul: "Woah, sorry dude. No need to manstruate at me- I'll clean it up!"
James: "Dude, what's up with Jeff? He's been really crabby lately."
Harry: "Yea, I know. He's probably manstruating."
When a man who is normally quite kind and level headed, goes completely moody and rude for a couple of days. They will have all the moodiness and irritability of a girl on her period, hence MANstrual cycle.
Person 1: Jeez, what's going on with Jim? He's never this moody.
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.