Urban Dictionary is definitely a relic of early mass adopted user-driven content. As a place where anyone can submit definitions for their own slang, Urban Dictionary’s appeal was catapulted by those people who wanted to be in-the-know with current speak.
Anyone not in the know has access to user submitted definitions, and now, not only can users define slang, they can also submit images to support their content.
So go to UrbanDictionary.com, and look up all the little things you ever wanted to know.