A creature who displays characteristics that include stupidity and ignorance of the situation and setting that they are in.
John: Wow that cow doesn't seem to do much, but eat grass. Hmmm, a cow that just eats grass.

Al: Yes John, that type of bovine is called a maddnism.

John: Why? Is that a good thing?

Al: No, John that is a bad thing.

John: Oh, like a half back trying to tackle his quarterback, or me commentating games.

Al: Yes John.
by Ghostface Slinger January 30, 2009
Get the Maddnism mug.