From the 1930's (circa). Refers to a person of questionable intelligence. The size of the brain being given relative size of a human knuckle. Similar to pinhead.
That guy just sat on a bench with wet paint. What a knucklehead.
by The Phat Doctor December 27, 2004
Get the mug
Get a knucklehead mug for your cousin Manafort.
A dunce. A dummy. A very stubborn person or animal.
I told him how to do it, but he would not listen, the knucklehead!
by Merrily McCarthy July 17, 2003
Get the mug
Get a knucklehead mug for your daughter-in-law Jovana.
Engine produced by the Harley Davidson Motorcycle Company from(1936 to 1947). The engine consists of an overhead-valve v-twin design with covers on the valves that resembled knuckles, hence the name of "knucklehead".
Mike's knucklehead got repo'd after he missed his second payment
by The B-rad October 13, 2006
Get the mug
Get a knucklehead mug for your guy Larisa.
someone who is irresponsible and acts ignorant
Don't be a knucklehead you understand what's being said.
by Gerard Irick October 19, 2010
Get the mug
Get a knucklehead mug for your friend José.
the punching of a boner in attempts to make it go away.
dude I got a boner in the parking lot so I gave myself some knucklehead to make it go away.
by knuckleheadwittness January 26, 2012
Get the mug
Get a knucklehead mug for your coworker Zora.
An honors physics student of ability but who lacks the conventional expression of said ability (i.e. homework completion, class appropriateness). May or may not get high grades.
6th period lost its elder knucklehead after 1st semester
by Pelota January 29, 2010
Get the merch
Get the knucklehead neck gaiter and mug.