1. The awkward, goofy-looking version of yourself.
2. Your twin with Downs Syndrome.
3. When you see someone you think you know out of the corner of your eye, only to realize upon closer inspection that the person is in fact a derp-y version of the friend you thought you saw. This is your friend's derpelganger.
I totally thought I saw you stumbling around drunk by the mall today, but it turns out it was your derpelganger.
by Dino_Pravo June 25, 2012
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