hammerhead (noun)
1: these words are used to express a low opinion of someone's intelligence [syn: dunce, dunderhead, numskull, blockhead, bonehead, lunkhead, knucklehead, loggerhead, muttonhead, shithead, fuckhead]
2: the striking part of a hammer
3: medium-sized live-bearing shark with eyes at either end of a flattened hammer-shaped head; worldwide in warm waters; can be dangerous [syn: hammerhead shark]