\ˈnäk \
knocked; knocking; knocks

Definition of knock 

(Entry 1 of 2)

intransitive verb

1 : to strike something with a sharp blow

2 : to collide with something

3a : bustle heard them knocking around in the kitchen

b : wander knocked about Europe all summer

4a : to make a pounding noise

b : to have engine knock

5 : to find fault

transitive verb

1a(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

2 : to cause to collide

3 : to find fault with always knocking those in authority

knock cold knock dead

: to move strongly especially to admiration or applause a comedian who really knocks them dead

knock for a loop

1a : overcome knocked my opponent for a loop

b : demolish knocked our idea for a loop

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

knock one's socks off

: to overwhelm or amaze one a performance that will knock your socks off

knock on wood

used interjectionally to ward off misfortune

knock together

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



Definition of knock (Entry 2 of 2)

1a : a sharp blow : rap, hit a loud knock on the door

b(1) : a severe misfortune or hardship

(2) : setback, reversal

2a : a pounding noise

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

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

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Synonyms & Antonyms for knock

Synonyms: Verb

blame, censure, condemn, criticize, denounce, fault, pan, reprehend

Synonyms: Noun

adversity, ill, misadventure, mischance, misfortune, mishap, tragedy

Antonyms: Verb

extol (also extoll), laud, praise

Antonyms: Noun

fortune, luck, serendipity

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Examples of knock in a Sentence


The ball knocked him on the chin. She knocked the glass from his hand. He knocked the baseball over the fence. The ball hit him in the mouth and knocked out one of his teeth. The wind knocked him backwards. The dog knocked against the lamp. My knee accidentally knocked against the table. Skaters were knocking into each other all over the ice. I accidentally knocked my knee against the table.


He gave him a knock on the head. There was a loud knock at the door. She took some knocks early in her career. He likes praise but can't stand the knocks.
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Recent Examples on the Web: Noun

Down Youssouf Sabaly takes a knock and is slowly being led off the field. Joel Petterson, New York Times, "Colombia Emerges From the World Cup Chaos, Booting Senegal," 29 June 2018 However, while on international duty with England, Gomez suffered an injury setback, taking a knock to his ankle., "Liverpool Offered Huge Injury Boost as Star Defender Returns to Melwood After Ankle Surgery," 26 June 2018 But in 2016, the lab took a knock when its main facility, the National Spherical Torus Experiment (NSTX), developed a series of disabling faults shortly after a $94 million upgrade. Daniel Clery, Science | AAAS, "Knighthood in hand, astrophysicist prepares to lead U.S. fusion lab," 19 June 2018 Either way, the government’s reputation has taken a knock. The Economist, "British railways are reduced to chaos by a botched timetable change," 7 June 2018 Wenger finally made a switch as the fit-again Lacazette came on for Welbeck, while Diouf, having taken a knock, was replaced by Saido Berahino. Afp,, "Aubameyang brace leads late Arsenal win over Stoke," 1 Apr. 2018 But as competitors took heed and raised the sophistication of their sedans, the ES took its share of knocks from drivers who wanted more dynamic handling. Jeff Yip, Houston Chronicle, "Posher, sleeker 2019 Lexus ES will have Apple CarPlay, Amazon Alexa," 16 June 2018 Standing at least three feet tall, these were not the plastic knock-offs towns hand out nowadays. Longreads, "The Cold War and its Fallout," 16 June 2018 One of the main knocks against Nest’s comprehensive smart home security system, the Nest Secure, has been its high cost. Chris Welch, The Verge, "Nest drops price of its home security system to $400," 11 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'knock.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of knock


before the 12th century, in the meaning defined at intransitive sense 1


14th century, in the meaning defined at sense 1a

History and Etymology for knock


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

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Statistics for knock

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Time Traveler for knock

The first known use of knock was before the 12th century

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More Definitions for knock



English Language Learners Definition of knock

 (Entry 1 of 2)

: 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



English Language Learners Definition of knock (Entry 2 of 2)

: 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


\ˈnäk \
knocked; knocking

Kids Definition of knock

 (Entry 1 of 2)

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

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

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

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

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

knock down

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

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

knock off

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

knock over

: to cause to fall



Kids Definition of knock (Entry 2 of 2)

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

2 : a sharp blow a knock on the head

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


\ˈnäk \

Medical Definition of knock 

1 : a sharp blow a knock to the head

2 : a sharp pounding noise

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More from Merriam-Webster on knock

Thesaurus: All synonyms and antonyms for knock

Spanish Central: Translation of knock

Nglish: Translation of knock for Spanish Speakers

Britannica English: Translation of knock for Arabic Speakers

Comments on knock

What made you want to look up knock? Please tell us where you read or heard it (including the quote, if possible).


one that holds something together

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