(noun) A thin, wispy moustache, usually hugging the lipline. Just a few hairs thick, and usually extends no further to the sides than the mouth does.
Usually the only facial hair that 14- or 15-year-olds can grow, it is left unshaven as a display of how manly the child has become.
Though occasionally worn by grown adults, the mandammit is the hallmark of teenagers insecure about themselves, but proud that they can grow facial hair. These teenagers are usually male.
"I am a MAN! DAMMIT! Don'cha see my friggin' sweet 'STASH?!?"
Kevin Federline has a mandammit, two kids with Brittney Spears, and absolutely no talent.