knocker Meaning, Definition & Usage

  1. noun (Yiddish) a big shot who knows it and acts that way; a boastful immoderate person
  2. noun a person who knocks (as seeking to gain admittance)
    • open the door and see who the knocker is
  3. noun one who disparages or belittles the worth of something
    depreciator; disparager; detractor.
  4. noun either of two soft fleshy milk-secreting glandular organs on the chest of a woman
    titty; tit; bosom; breast; boob.
  5. noun a device (usually metal and ornamental) attached by a hinge to a door
    doorknocker; rapper.

WordNet

Knock"er noun
Definitions
  1. One who, or that which, knocks; specifically, an instrument, or kind of hammer, fastened to a door, to be used in seeking for admittance.
    Shut, shut the door, good John ! fatigued, I said; Tie up the knocker; say I'm sick, I'm dead. Pope.

Webster 1913