knucklehead(n = noun.person) blockhead, bonehead, dumbass, dunce, dunderhead, fuckhead, hammerhead, loggerhead, lunkhead, muttonhead, numskull, shithead - a stupid person; these words are used to express a low opinion of someone's intelligence;
is a kind of dolt, dullard, pillock, poor fish, pudden-head, pudding head, stupe, stupid, stupid person