(noun) - a mustache developed by prepubescent boys that resembles a smudge of scum across his upper lip. they can usually be found on Chibi Kuririns.
Chibi, go shave that wretched scumstache.
by DreDizzle324 October 03, 2005
Noun- when a man does not have a fully developed mustache, instead he has peach fuz like hairs, that are usually dirty, on his upper lip. Most commonly seen on mexicans, 11-13 year old boys, and people who are down right hideous.
wow hes been trying to grow out a mustache for weeks and all its turnd out to be is dirty scumstache
by Jack R December 18, 2006