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verb \ˈnäk\

Simple Definition of knock

  • : to hit something (such as a door) with the knuckles of your hand or with a hard object (such as a knocker) in order to get people's attention

  • : to hit (something or someone) in a forceful way

  • : to touch or hit someone or something in a way that is not planned or intended

Source: Merriam-Webster's Learner's Dictionary

Full Definition of knock

  1. intransitive verb
  2. 1 :  to strike something with a sharp blow

  3. 2 :  to collide with something

  4. 3 a :  bustle <heard them knocking around in the kitchen> b :  wander <knocked about Europe all summer>

  5. 4 a :  to make a pounding noise b :  to have engine knock

  6. 5 :  to find fault

  7. transitive verb
  8. 1 a (1) :  to strike sharply (2) :  to drive, force, or make by or as if by so striking <was knocked out of the campaign> b :  to set forcibly in motion with a blow

  9. 2 :  to cause to collide

  10. 3 :  to find fault with <always knocking those in authority>

knock cold

  1. :  knock out 2a(1)

knock dead

  1. :  to move strongly especially to admiration or applause <a comedian who really knocks them dead>

knock for a loop

  1. 1 a :  overcome <knocked my opponent for a loop> b :  demolish <knocked our idea for a loop>

  2. 2 :  dumbfound, amaze <the news knocked them for a loop>

knock one's socks off

  1. :  to overwhelm or amaze one <a performance that will knock your socks off>

knock on wood

  1. —used interjectionally to ward off misfortune

knock together

  1. :  to make or assemble especially hurriedly or in a makeshift way <knocked together my own bookcase>

Examples of knock in a sentence

  1. The ball knocked him on the chin.

  2. She knocked the glass from his hand.

  3. He knocked the baseball over the fence.

  4. The ball hit him in the mouth and knocked out one of his teeth.

  5. The wind knocked him backwards.

  6. The dog knocked against the lamp.

  7. My knee accidentally knocked against the table.

  8. Skaters were knocking into each other all over the ice.

  9. I accidentally knocked my knee against the table.

Origin and Etymology of knock

Middle English knoken, from Old English cnocian; akin to Middle High German knochen to press

First Known Use: before 12th century




Simple Definition of knock

  • : a hard, sharp hit

  • : the sound made by a hard hit

  • : an experience that makes you less confident or successful for a period of time : a difficult or painful experience

Source: Merriam-Webster's Learner's Dictionary

Full Definition of knock

  1. 1 a :  a sharp blow :  rap, hit <a loud knock on the door> b (1) :  a severe misfortune or hardship (2) :  setback, reversal

  2. 2 a :  a pounding noise b :  a sharp repetitive metallic noise caused by abnormal ignition in an automobile engine

  3. 3 :  a harsh and often petty criticism <the knock on him was that he couldn't handle the pressure>

Examples of knock in a sentence

  1. He gave him a knock on the head.

  2. There was a loud knock at the door.

  3. She took some knocks early in her career.

  4. He likes praise but can't stand the knocks.

14th Century

First Known Use of knock

14th century

KNOCK Defined for Kids



verb \ˈnäk\

Definition of knock for Students



  1. 1 :  to strike in order to get someone's attention <I knocked before entering.>

  2. 2 :  to bump against something without intending to <Careful! You knocked the lamp.>

  3. 3 :  to make a pounding noise <The car's engine began knocking.>

  4. 4 :  to find fault with <Don't knock it till you try it.>

  5. 5 :  to hit forcefully <He knocked the ball out of the park.>

knock down

  1. 1 :  to strike to the ground with or as if with a sharp blow

  2. 2 :  to take apart <Knock down the tent before you leave camp.>

knock off

  1. :  to stop doing something <Hey, I don't like that, so knock it off!>

knock over

  1. :  to cause to fall




Definition of knock for Students

  1. 1 :  a pounding noise <I heard a knock at the door.>

  2. 2 :  a sharp blow <a knock on the head>

  3. 3 :  a difficult or painful experience <You learn from life's knocks.>

Medical Dictionary


noun \ˈnäk\

Medical Definition of knock

  1. 1:  a sharp blow <a knock to the head>

  2. 2:  a sharp pounding noise

Learn More about knock

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