A FAIL (less commonly on the internet known as a fail) is something that is not a win. A FAIL is when Somebody does something really stupid and/or pathetic. FAILS are laughed at by Everybody, and make the person who did the FAIL feel really dumb. FAILS are extremely common in the UnWorld and everywhere else, because people in general are really stupid.
You probably FAIL all the time. The only person who is immune to FAILS is Chuck Norris. He has never FAILED in the history of the UnUniverse. Just about everyone else FAILS all the time. Albert Einstein even came up with the Theory of FAIL, a theory that proves the world is entirely dependent on the FAILS of stupid people. By the way, reading this article was a FAIL in itself because you have no life.