a mustache that is so ingrained with white trash DNA, it grows in weak, with only a small number of thin hairs as compared to a normal mustache. I.E.-Cletus the slack-jawwed yokel has a crustache.
The pathetic looking prepubescent mustache sported by boy bands and male high school students intended to impress women, while drawing only jeers and snickers. See peach fuzz.
Zach's dad finally made him Nair his crustache, he looked like a queer!
(n) When a man ejaculates on another man's mustache and then doesn't clean it off, alowing it to dry.
man 1: "Gee wiz it sure is a boring day with nothing ta do."
man 2: "Sure is...Yo dude I know what we can do. Why don't I give you a crustache?"
man 1: "I don't see why not!"
A crusty little mustache that can't be grown full enough to be dubbed a full fledged mustache. Usually worn by teenagers or white trash Joe Dirt types that cant grow facial hair but wont take mother natures no for an answer.
A crusty, messy, weird looking mustache.
Mustaches that have lint and crumbs in them.
Guy 1: "See that geezer over there?"
Guy 2: "Yeah, what about him?"
Guy 1: "See all those crumbs in his mustache? Now that, my friend, is a crustache."