noun (n)

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

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

  source: wordnet30
• One backward in book learning; a child or other person dull or weak in intellect; a dullard; a dolt.(noun)

  source: webster1913