(n.) One who is apt to blunder.

addlebrain addlehead addlepate beefhead blubberhead blunderer blunderhead bonehead boor botcher bufflehead bumbler bungler cabbagehead chowderhead chucklehead clod clodhead clodhopper clodknocker clodpate clodpoll clot clown dimwit dolt dolthead dullhead dumbbell dumbhead dummy dunderhead dunderpate fathead fumbler gawk gowk jolterhead jughead klutz knucklehead looby lout lubber lunkhead meathead muddlehead mushhead muttonhead nitwit noodlehead numskull oaf ox peabrain pinbrain pinhead puddinghead pumpkin head puzzlehead slouch slubberer stupidhead thickhead thickskull tottyhead yokel