Derived from the word dumbass. Used to describe an individual who radiates extreme levels of dumbass. Can be refered to as a medical condition.
"So in the middle of the night, the phone rang, he went to grab it, grabbed his Smith & Wesson 38. and blew off his head? He's got a bad case of dumbassism"
by JTF2Lonewolf June 20, 2004