A contraction of the words male and onion-booty. Used to describe a man's ass that looks so good it makes you want to cry.
That guy's monion is as fine as any woman's booty.
by Mandingo_DeSade August 25, 2010
a monion is when a guy is having sex with a girl with a fake eye and when hes about to come she takes out her eye and he comes in it
when m monion and u mom get in on and then we fuck and fuck and fuck
by kangi October 15, 2007