\ ˈnäk How to pronounce knock (audio) \
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

Keep scrolling for more

Examples of knock in a Sentence

Verb 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. Noun 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.
See More
Recent Examples on the Web: Verb People would often call or knock on her door, asking for help for relatives. New York Times, "Gladdie Fowler, Educator and Mental Health Advocate, Dies at 69," 23 Jan. 2021 And a 17-point collapse against a Steelers squad that looked lifeless throughout the first 40 minutes of the game might just knock the Colts right out of the postseason. Lorenzo Reyes, USA TODAY, "NFL Week 16 winners and losers: Is Packers QB Aaron Rodgers running away in MVP race?," 28 Dec. 2020 The Blazers knock the ball away from Harden with 21.4 seconds left. oregonlive, "CJ McCollum, Damian Lillard lead Portland Trail Blazers to overtime win against Houston Rockets: Live updates recap," 26 Dec. 2020 Jordan Spieth and Rafael Cabrera Bello both had a chance to knock a bunch of people out of the weekend, including each other. Paul Newberry, Star Tribune, "Tiger's quest for sixth Masters title will have to wait," 14 Nov. 2020 Justice Amy Coney Barrett will be settling into her new chair, knock on wood, precluding a 4-4 split. The Editorial Board, WSJ, "The Supreme Court’s Election Dodge," 20 Oct. 2020 People used to knock on her door at all hours of the night, asking for a drug dealer who does not live there. Washington Post, "Segregated from opportunity," 15 Oct. 2020 The neutrons might smash and knock loose protons in a person’s tissue, transmitting momentum like billiard balls, Wimmer-Schweingruber says. Adam Mann, Science | AAAS, "Moon safe for long-term human exploration, first surface radiation measurements show," 25 Sep. 2020 Officials claim that volunteers knock on one million doors per week, while the Biden campaign has forgone door to door canvassing so far during the pandemic. Sarah Ewall-wice, CBS News, "Trump's reelection bid blew through $830 million before Labor Day," 9 Sep. 2020 Recent Examples on the Web: Noun June 11, 2020The Louisville Metro Council voted unanimously to pass Breonna's Law that bans no-knock warrants and requires that police turn on their body cameras before carrying out a search. Siladitya Ray, Forbes, "House’s Sweeping Police Reform Act Underpins Swathe Of Similar Local Legislation Passed Since George Floyd’s Death," 4 Mar. 2021 The House bill bans no-knock warrants in drug cases and police chokeholds. Jason Silverstein, CBS News, "The only Republican to vote for George Floyd police reform act says he "accidentally" pressed the wrong button," 4 Mar. 2021 Last week, the Kentucky Senate passed legislation, Senate Bill 4, that would ban some no-knock warrants. Hayes Gardner, The Courier-Journal, "Breonna Taylor protesters caravan to Frankfort to support total ban on no-knock warrants," 3 Mar. 2021 The legislation would ban chokeholds, carotid holds and no-knock warrants at the federal level. Donna Owens, Essence, "Rep. Karen Bass Reintroduces George Floyd Policing Bill in Congress," 26 Feb. 2021 Jones’s omnibus bill includes the repeal of the bill of rights but also a body camera requirement, a use-of-force policy that bans chokeholds and restricts no-knock warrants, and other reforms. Washington Post, "Push for police reform creates rift in Maryland’s Democratic caucus," 10 Feb. 2021 The no-knock warrants, which allow officers to burst into a home without announcing, have since been banned by Louisville's Metro Council in a law named for Taylor. Dylan Lovan, Star Tribune, "Kentucky to study warrant process after Taylor shooting," 21 Jan. 2021 In July, police officials pushed back against efforts to abolish or curtail their no-knock warrants — helping carve out a wide range of investigations for which they could still be used. Washington Post, "Maryland SWAT officer cleared in fatal shooting of Duncan Lemp during execution of no-knock warrant," 31 Dec. 2020 Breonna’s Law would end the use of no-knock warrants across the entire state. Anoa Changa, Essence, "‘Slow Justice’ As Officers Responsible For Killing Breonna Taylor Face Possible Termination," 30 Dec. 2020

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.

See More

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

Keep scrolling for more

Learn More about knock

Time Traveler for knock Time Traveler

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

See more words from the same century

Statistics for knock

Last Updated

8 Mar 2021

Cite this Entry

“Knock.” Dictionary, Merriam-Webster, Accessed 9 Mar. 2021.

Style: MLA
MLA Chicago APA Merriam-Webster

Keep scrolling for more

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


\ ˈnäk How to pronounce knock (audio) \
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 How to pronounce knock (audio) \

Medical Definition of knock

1 : a sharp blow a knock to the head
2 : a sharp pounding noise

Keep scrolling for more

More from Merriam-Webster on knock

Thesaurus: All synonyms and antonyms for 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).


Test Your Vocabulary

Who Knew?

Spell It

Can you spell these 10 commonly misspelled words?

 AlphaBear 2

Spell words. Make bears.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!