S.W.I.M.

Acronym meaning: Someone Who Isn't Me
But general use indicates that it is indeed the same person.

S.W.I.M. decided to walk his dog today.

by KazerDragon April 16, 2008

S.W.I.M.

an acronym for "Sleeps With Men". Your a dumbass if you can't figure out the "I" is in teh word "with" like "S.E.A.L." where as the "S.E." is for "Sea".

Vince and mike went swimming last night.

by Shil April 10, 2004