A dumbass.  A person of questionable intelligence, usually a male for obvious reasons.  If reason is not obvious, perhaps you are a numbnut.
by Matt Heller December 17, 2003
 Get the numbnutmug.
Get the numbnutmug. Correct spelling of numnut. Normally used as an insult meaning idiot. However, also implies that the recipient is a coward, sterile or impotent. A combination of numb and nut, where nut is a slang for testicle. In other words, a man who cannot feel his testicles and acts accordingly.
by wkc December 1, 2006
 Get the numbnutmug.
Get the numbnutmug. This word originated in the U.S, however, it's used in the U.K. as well. Most likely its use was born in the U.S. military, just as expressions like soup sandwich and jeep. Made popular in the movie, "Full Metal Jacket," when Hartman yells at Pyle.
"What is your major malfunction, numbnut?!"
by pedicabber April 22, 2005
 Get the numbnutmug.
Get the numbnutmug. "I hear that Johnny shot himself in the head while cleaning out a loaded shotgun before he headed out for the opening of dear season, what a numbnut!"
by btezra October 25, 2002
 Get the numbnutmug.
Get the numbnutmug. by maximorph April 23, 2003
 Get the numbnutmug.
Get the numbnutmug. A guy who's had his balls busted so many times he doesn't even feel it any more. Often mistaken for a perennial loser. This group is ranked among the lowest in the male social strati.
by Hobgoblin88 July 2, 2011
 Get the numbnutmug.
Get the numbnutmug. The parents of the retarded boy decided to have him castrated when he was seen humping a dog.  He is now a numbnut.
by Richard Black March 28, 2005
 Get the numbnutmug.
Get the numbnutmug.