noun (n)

• a stupid person; these words are used to express a low opinion of someone's intelligence(noun.person)

  Synonym:
  bonehead, dumbass, dunce, dunderhead, fuckhead, hammerhead, knucklehead, loggerhead, lunkhead, muttonhead, numskull, shithead
  

  source: wordnet30
• A stupid fellow; a dolt; a person deficient in understanding.(noun)

  source: webster1913