Has a similar meaning to "fucker"
"Oh my God, You derf! What the hell did you just do? You Fucked everything up!"
by Emily May 06, 2003
One stupid ass fucked up bitch, who doesnt know what she wants, lies all the time, tells you she likes you... but then sometimes wants to get on other people...
Man... she is such a Derf!
by Derf Hater March 10, 2003
a retartedly, annoying white girl; usually very ugly
that stalker gurl is a mad derf
by Anonymous March 08, 2003