A person who has nothing better to do than to continuously attempt to create funny definitions at Urban Dictionary all day but failing due to their own overzealous efforts.
Mostly teenagers but not exclusively, these people will begin to suffer from withdrawal symptoms similar to a drug addict's if they do not get their share of thumbs-up but in their pathetic desperation to attain acceptance, they fail and are further exiled from society.
This also includes the thumbs-down trolls, as their need to try and belittle other people's definitions, no matter how accurate, is the result of their own failure at Urban Dictionary and at life, which to them are apparently one in the same.
= "I'm going to thumbs-down this bitch's definition."
Human = "Why?"Toolbox
= "Because they thumbs-down'd my fucking shit when it's flawless. Read it."
*Reads an essay's worth of words for a single definition filled with retarded grammatical errors, overuse of shitty internet memes, dumb inside jokes and a lack of humor*
Human = "Well, I found the reason why, dude. You're a UDTH (Urban Dictionary Try-Hard)."