A definition on urban dictionary that has absolutely no relation to what you may think it is at first glance. Usually very annoying to see. Usually defines name for a drug used solely by the writer and no-one else on earth. Often mixed with definitions relating to what it actually means. More than likely will generate a situation similar to "thumbs up < thumbs down". For a real-life example, see roller coaster #5.
guy 1: I found a defagnition on UD yesterday...
guy 2: What did it say?
guy 1: "assault rifle: a joint that's as long as an AK-47". It had 200,000 thumbs down, and 3 thumbs up.
guy 2: fag....
A real person's name, posted to the www.urbandictionary.com web site as a supposed slang phrase, intended for the sole purpose of slandering or insulting that person. Usually not in use by any one other than the original poster.
That Mindy Minsky is such a bitch, I'll make sure that her name is a defaminition after I get home from school. "Mindy Minsky: skanky-assed whore who bones the janitor."