bone"head*ed*ness
Webster's Dictionary (GCIDE)
boneheaded \bone"head*ed\ adj. very stupid; -- used of people or actions. [informal] -- bone"head*ed*ness, n.
Syn: blockheaded, fatheaded, loggerheaded, thick, thickheaded, thick-skulled, wooden-headed. [WordNet 1.5] bone-idle