noun (n)

• (Yiddish) a big shot who knows it and acts that way; a boastful immoderate person(noun.person)

  source: wordnet30
• a person who knocks (as seeking to gain admittance)(noun.person)

  Example:
  Open the door and see who the knocker is.
  

  source: wordnet30
• one who disparages or belittles the worth of something(noun.person)

  Synonym:
  depreciator, detractor, disparager
  

  source: wordnet30
• either of two soft fleshy milk-secreting glandular organs on the chest of a woman(noun.body)

  Synonym:
  boob, bosom, breast, tit, titty
  

  source: wordnet30
• a device (usually metal and ornamental) attached by a hinge to a door(noun.artifact)

  Synonym:
  doorknocker, rapper
  

  source: wordnet30
• One who, or that which, knocks; specifically, an instrument, or kind of hammer, fastened to a door, to be used in seeking for admittance.(noun)

  source: webster1913
• A person strikingly handsome, beautiful, or fine; one who wins admiration; a "stunner."(noun)

  source: webster1913