What makes UrbanDictionary so unique is it's actually written by its users. You could submit a word right now. I submitted a word once, soshob. ...It never quite took off, but did receive 7 thumbs up.
On this blog, you will find definitions to the words you need to know that are commonly used today. You will also find links to the best resources, including UrbanDictionary.
If you're unsure the definition of a word you heard, this is the place to find the answer!