A girl that a sorority says 'FUCK NO' to but then somehow ends up on the bid list. Basically sneaks into the sorority, like a ninja would.
Fratdaddy: 'Holy hell, how did that squirrelly looking girl get into (insert hot/good sorority here)'?
Slampiece: 'She's a sorority ninja. We don't know either'
Slampiece: 'She's a sorority ninja. We don't know either'
by shadypi October 25, 2010
Get the sorority ninjamug.