Slow of mind, lacking interest or point. Lacking common knowledge. Possibly a victim of brain damage.
"YO SHANEQUIA, Isn't that girl so mo0sy!?"
by Jadyyn Gangrape March 20, 2005
Comes from the latin words moooretarded, and syyyisdumb, which means to be dumb. see stupid.
psh, Becky, don't pull a mo0sy, now.
by le raerae. March 21, 2005
One or something that seems brilliant, in style, and considered vogue to peers
WOAH! That's SO mo0sy!!!
by Farrah March 21, 2005