An outfit normally worn by douchebags that hang out at places that they don't belong. For example, your mom's birthday party, or your cousin's bah-mitzvah.
Douchefits can contain (but are not limited to) leather pants, platform shoes, spiked bracelets and choke-collars, wallet chains, concert t-shirts, jeans that are too small for you, things bought from Gadzooks mall stores, etc.
"Dude, yesterday at my cousin's graduation party, Camden (<--- douche name) showed up in a total douchefit thinking it would get him laid. What a fuckin' loser."