Ever been in a situation, either as a kid/teenager or as an adult and had a word come up on tv/in conversation/in a song that left you confused? And not just a word like majuscule that can be looked up in a dictionary, a word like "milf" or "newb" that has more or less been made up by popular society. Urbandictionary* is basically the answer to that problem, which can be good and bad.
Really this site is best for high school students, college students, and adults. There is a lot of content involving sex, drugs, and alcohol on this site, and for once I think Common Sense has underestimated. There is a word of the day posted on the home page of the site, which may or may not be tame. Also the definitions are free for people to type out, and these often include bias and personal opinion (such as the entries for Miley Cyrus or George W Bush). Still, the site is not inherently bad, and pretty darn useful. The content is just such that I wouldn't recommend usage for anyone who still doesn't know where babies come from.
Have you ever heard the term TMI? That's what this site is . . .
I have occasionally use this site when I wonder the *real message* behind popular songs. I wouldn't recommend this site for young teenagers. Although some may find it to be funny, almost every entry I've read is very vulgar. It could be a great education for parents, though, if they hear their teenagers mention a term that they don't recognize. Warning though, I have often discovered that I was better off not knowing the real meaning behind the words.
Slang is, by definition, "the language of the rebel, the outlaw, the despised, the marginal, the young...the language of the city (Jonathon Green, _Cassell's Dictionary of Slang_)." So users shouldn't be surprised when using a site called Urban Dictionary that it mostly contains words that refer to sex, drugs, crime, violence, and other "inappropriate" behaviors. The key here is to teach kids about what these words are if/when the kids encounter them. Parents and educators should know about and use this site to their advantage--as a tool to learn what words are current among younger people, and as a teaching opportunity. Slang dictionaries are available in print, as well, and are equally as "offensive." Grab one off of your library's shelf and show a young person what it contains and *why* it contains what it does. Then, the curiosity is satisfied, and a dialogue has begun.