urban dictionary
An online dictionary that teenagers and college students make horrible slang entries for words. Their entries often are sexual, racist, anti-semetic, poorly written, and very vague. Shows one of the reasons why the world's education is steadily becoming worse.

Although Wikipedia is also editible by anyone, Wikipedia is a much better site to look for definitions. It's more of an encyclopedia, but their community is alot better than this site.
Urban Dictionary is 