Mantern 

Male intern

John hired a mantern this summer.

Mantern by ColleenV October 17, 2008

Manturnity 

When a man's gut is proportionately large for his size. This makes the man appear to be pregnant. Especially when they have skinny legs and no butt.

Bob's gut is getting bigger. Time to get some manturnity cloths.

Manturnity by Taekwondoka July 8, 2014

mantercourse

The act of intercourse between two or more men.

Stephen and Todd had violent mantercourse on your couch last night. I probably won't sit there anymore.

mantercourse by ktrane May 18, 2006

Mantenance 

Any form of male grooming.

"Yo dude, I gotta run. Gonna do some mantenance. Gotta be tough on the scruff!"

Mantenance by joshinatorg January 29, 2009

maternal fornicator

polite way of addressing sombody as a "motherfucker"

Which one of you Maternal Fornicators took my Bible?

maternal fornicator by vernon dutton January 20, 2004

mantenna

A man's penis, specifically in the erect position.

My mantenna is detecting some estrogen in the area, so I should follow it to find the girl of my dreams.

mantenna by Marcus Solomon November 19, 2007

masternap

The act - either planned or unplanned - of falling to sleep after masturbating.

I was just going to rub one out, but I ended up masternapping for an hour.

Bob's been away from his wife for two days, so he went upstairs for a masternap.

masternap by ScottNWDC June 9, 2011