A person with an extreamly large head that is shaped like a rectangle or square. Can often be mistaken for a large mallet that is used to tenderise meat. These people will always be the social retard of every event they attend. They don't understand the concept of socialicing. If insulted they will often question you about it the next day on MSN or AIM.
Man 1: Why is the sun actually hitting my face today?
Man 2: It's because Eric and his mallet head are missing today
Man 2: It's because Eric and his mallet head are missing today
by Chesstastic June 29, 2007
Definition: a person whose head is a rectangle,or the head itself. Also used to mean a person with a vacuous mind. A mad scientist would be a good example of a mallethead.
"If I had known you were only going that far,mallethead, I would have stayed in,"Amy told her friend Jim,after he fell out of the cardboard box and lost his pompom snowhat,due to his big mallethead,as he tried to boxslide downhill by himself. Down below,at the bottom of the snowy hill,Pat and Gary,wearing plain snowhats and overcoats,thought,"What a malletheadJim is, partly for wearing a pompom snowhat,and a jacket! Plain snowhats and overcoats are the ideal winter gear these days! Well,at any rate,Jim deserves to lose his hat, since his head is a mallethead and he is a mallet head!"
by JMC70 October 26, 2016
He is a mallet head; someone who couldn't pour piss out of a boot if the instructions were written on the heel.
by T. G. Moore October 27, 2006