M.O.S.

Member of Opposite Sex.

I have engaged in foreplay with an M.O.S.

by Dash_Morlock July 21, 2010

M.O.S.

Make Out Session. Normally takes place while intoxicated. Not to be confused with F.O.S which is a fire up session, or a F.I.S. (when you fire inside a girls guts, deposit your kids in the women's belly).

We M.O.S.'ed (pronounced mossed) for a long time.

by Brian Dbag Peters April 22, 2006

M.O.S.

man of steel (or 'men')

the 'macho man' who has huge pain tolerance, physically OR emotionally!; ESPECIALLY WHEN DRUNK!!

jack was a true M.O.S.!! he took on some killer bikers and got seriously thrashed, but bounced back like a turd that wouldn't flush!

he didn't know what he was in for challenging those M.O.S.

the special op M.O.S. kept on shooting after losing part of a leg, until he keeled over from blood loss!

by michael foolsley February 12, 2010

M.O.S.

M.O.S.=Member of Society:

someone who works, doesn't live with his parents and has a girlfriend. As well as this he does things regualr people do like go to the gym, wear a suit to work and buys beers in rounds at the pub.

that boy wears a suit to work, he's an M.O.S.

I saw him jogging with his girlfriend, what an M.O.S.

mate he's busy being an M.O.S. he ain't gonna come out.

by Safety190 September 1, 2010

M.O.S

Multiple Orgasm Syndrome -

An ever-looming threat that hangs around the corner for all of us. Happens whenever we see someone wearing a comically sexy outfit such as jorts or socks and sandals. Results in a lot of cumming and moaning and is uncontrollable.

"Bro you shouldn't wear those jorts you don't wanna give the ladies M.O.S."

by ahahano October 12, 2019

M.O.S

millennial outrage syndrome (MOS): the constant need to find outrage in everything all the time.

Jeff has a raging case of M.O.S.

by E Towne August 31, 2019

M.O.S

Some one who is not related to you but is older mentally and is close enough to be your sister.

Sarah is My M.O.S

by Savage16 May 30, 2016