A troll who down votes comments/submissions for the sole purpose of angering and confusing people.
I log on UD today and I see lots of words of the day's down voted. Looks like the work of a down voter troll.
Someone who goes on Urban Dictionary and down votes EVERY definition just because that's what they do. It does not matter if it is the correct definition they will still down vote it.
Guy 1: Hahaha look at that definition it's so funny!
Guy 2: I'm down voting it.
Guy 1: Not cool, why would you do that?
Guy 2: Because i am a down voter