look up any word, like timebomb:
 
2.
somone who is from the southshore massachuset. These people are faggets and can go fuck themselves. the word is a mix of martians and people from mass(massins).
most niggers from duxbury are massins.
by i love sam <3 July 01, 2011
 
1.
Super hot exotic guy with nice abs and amazing hair. He's hilarious, has deep dark eyes, and a great laugh. Every girl tears themselves apart for him, because he's so amazing.
Hey did you see Massin yesterday?
Ya he looked even hotter than he usually does, if that's even possible!
by Thebestever March 31, 2014
 
3.
an abbreviation for the term masterbating
"dude i'll catch you later i'm massin"
can be used with a "t" replacing the "in"
i.e. "sorry man i have to go masst it"
by jake strange January 08, 2008