from The American Heritage® Dictionary of the English Language, 5th Edition.

  • intransitive verb To strike with a hard blow.
  • intransitive verb To affect in a specified way by striking hard.
  • intransitive verb To cause to be displaced or unengaged; force.
  • intransitive verb To cause to collide.
  • intransitive verb To produce by hitting or striking.
  • intransitive verb Informal To find fault with; criticize.
  • intransitive verb To strike a sharp audible blow or series of blows, as on a door.
  • intransitive verb To collide with something.
  • intransitive verb To make a pounding or clanking noise.
  • noun An instance of striking or colliding.
  • noun The sound of a sharp blow on a hard surface.
  • noun A pounding or clanking noise made by an engine, often as a result of faulty fuel combustion.
  • noun Slang A cutting, often petty criticism.
  • idiom (have it knocked) To be certain of success.
  • idiom (knock cold) To render unconscious; knock out.
  • idiom (knock dead) To kill with a blow.
  • idiom Slang (knock dead) To affect strongly and positively.
  • idiom (knock it off) To stop doing something. Often used in the imperative.
  • idiom (knock out of the box) To force the removal of (an opposing pitcher) by heavy hitting.
  • idiom (knock (someone's) socks off) To overwhelm or amaze.
  • idiom (knock some sense into) To beat or hit (someone) in an effort to teach a lesson or cause a person to adopt an acceptable pattern of behavior.

from The Century Dictionary.

  • noun A blow; a buffet; a stroke with the fist, or with anything hard or heavy, as a cudgel, a hammer, or the knocker of a door.


from The American Heritage® Dictionary of the English Language, 4th Edition

[Middle English knokken, from Old English cnocian.]

from Wiktionary, Creative Commons Attribution/Share-Alike License

Akin to Old Norse knoka (compare Swedish knocka, Danish knuge, to hug) and Middle High German knochen, to hit.


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