knock
Americanverb (used without object)
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knocks,
present (3rd person singular)
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knocked,
past participle, past
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knocking
present participle
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to strike a sounding blow with the fist, knuckles, or anything hard, especially on a door, window, or the like, as in seeking admittance, calling attention, or giving a signal.
to knock on the door before entering.
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to strike in collision; bump.
He knocked into a table.
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to make a pounding noise.
The engine of our car is knocking badly.
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Informal. to engage in trivial or carping criticism; find fault.
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Cards. to end a game, as in gin rummy, by laying down a hand in which those cards not included in sets total less than a specific amount.
verb (used with object)
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knocks,
present (3rd person singular)
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knocked,
past participle, past
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knocking
present participle
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to give a sounding or forcible blow to; hit; strike; beat.
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to drive, force, or render by a blow or blows.
to knock a man senseless.
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to make by striking a blow or blows.
to knock a hole in the wall.
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to strike (a thing) against something else.
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Informal. to criticize, especially in a carping manner.
He's always knocking everything.
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British Slang. to astound; impress greatly.
noun
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knocks
plural
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an act or instance of knocking.
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the sound of knocking, especially a rap, as at a door.
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a blow or thump.
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Informal. an adverse criticism.
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the noise resulting from faulty combustion or from incorrect functioning of some part of an internal-combustion engine.
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Cricket. an innings.
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British Slang.
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one of a combination of dealers who bid together, rather than against each other, at an auction, and later resell the purchases among themselves.
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an auction at which this is done.
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the sale of merchandise recently obtained by a dealer at an auction.
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verb phrase
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knock up
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Slang. to make pregnant.
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to exhaust; weary; tire.
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to damage; mar.
The children knocked up the new table.
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to injure; wound.
He was afraid to come home from school all knocked up again.
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British. to wake up; rouse; call.
He knocked us up before dawn.
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knock together to make or construct in a hurry or with little attention to detail.
He knocked together a couple of tables.
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knock around / about
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to wander aimlessly or idly; loaf.
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to mistreat (someone), especially physically.
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to jar; shake up.
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knock off
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Informal. to cease activity, especially work.
to knock off at five every day.
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to stop doing something; quit.
Knock it off or you'll get into a mess.
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Slang. to dispose of; finish.
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Slang. to murder; kill.
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Slang. to die.
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Slang. to get rid of; reduce.
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Slang. to disable or defeat.
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Slang. to commit a robbery at; steal from.
The gang knocked off a gas station.
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Nautical Slang. to blow the head (of a sailing vessel) off the wind.
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to imitate, copy, or plagiarize.
to knock off designer dresses in cheap materials.
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knock back to drink (a beverage), especially quickly and heartily.
He knocked back two shots of vodka.
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knock out
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to defeat (an opponent) in a boxing match by striking such a blow that the opponent is unable to rise within the specified time.
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to render (a person) unconscious.
Those sleeping pills knocked me out for ten hours.
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to make tired or exhausted.
Christmas shopping always knocks me out.
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Informal. to produce quickly, hurriedly, or with ease.
He knocks out two poems a day.
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to damage or destroy.
The explosion knocked out the power for several hours.
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knock over
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to strike (someone or something) from an erect to a prone position.
to knock over a lamp.
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to distress; overcome.
When the announcement came we were completely knocked over.
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Slang. to rob, burglarize, or hijack.
He knocked over five banks.
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knock down
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to sell at auction by a blow of the hammer or to a bidder.
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to take apart or disassemble, as for facility in handling, storing, shipping, etc.
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Slang. to receive, as a salary or a scholastic grade; earn.
He knocks down 30 grand a year.
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Informal. to lower the price of; reduce.
to knock down end-of-season leftovers.
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Slang. to embezzle or steal (money).
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to cause (a sailing vessel) to heel, as by a gust of wind, to such a degree that it cannot right itself.
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idioms
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knock out of the box, to cause a pitcher to be removed from the box because the pitcher has permitted too many hits to be made. Also knock out.
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knock the / one's socks off, to have an overwhelming effect on.
The song knocked the socks off the audience.
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have it knocked, to be assured of success.
With a government job, he thought he had it knocked.
verb
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(tr) to give a blow or push to; strike
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(intr) to rap sharply with the knuckles, a hard object, etc, esp to capture attention
to knock at the door
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(tr) to make or force by striking
to knock a hole in the wall
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to collide (with)
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(tr) to bring into a certain condition by hitting or pushing
to knock someone unconscious
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informal (tr) to criticize adversely; belittle
to knock someone's work
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Also: pink. (intr) (of an internal-combustion engine) to emit a characteristic metallic noise as a result of faulty combustion
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(intr) (of a bearing, esp one in an engine) to emit a regular characteristic sound as a result of wear
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slang to have sexual intercourse with (a person)
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informal to hit a person with a very heavy blow
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to have a violent or unpleasant encounter with (adverse facts or circumstances)
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to daze or kill (a person) by striking on the head
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effectively to prevent the further development of (a plan)
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noun
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a blow, push, or rap
he gave the table a knock
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the sound so caused
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the sound of knocking in an engine or bearing
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informal a misfortune, rebuff, or setback
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informal unfavourable criticism
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informal (in cricket) an innings or a spell of batting
Usage
What is a basic definition of knock? Knock is a verb that means to hit something by bumping into it. Knock also means to repeatedly strike something to make a noise. Knock is used as a noun to mean a sound made by repeated tapping. Knock has many other senses as a verb and a noun. It is also used in several idioms. Knock means to strike something by bumping into it or colliding with it. This sense of knock is often followed by what was bumped into (knocked onto the floor).
- Real-life examples: In bowling, the goal is to knock down all of the pins with a bowling ball. In boxing, the competitors repeatedly knock each other in the head and body with their fists. It is difficult to build a house of cards without accidentally knocking it over.
- Used in a sentence: Shawna wasn’t paying attention and accidentally knocked over a stack of boxes.
- Used in a sentence: He knocked on the wall with his umbrella to get everyone’s attention.
- Used in a sentence: I think you have a visitor because I heard a knock at the door.
Synonym Usage
See strike.
Other Word Forms
Derived Forms
Inflected Forms
Nouns
Participles
Conjugated Forms
Present
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knocksimple
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knockssimple
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have knockedperfect
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has knockedperfect
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am knockingprogressive
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are knockingprogressive
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is knockingprogressive
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have been knockingperfect progressive
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has been knockingperfect progressive
Past
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knockedsimple
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had knockedperfect
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was knockingprogressive
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were knockingprogressive
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had been knockingperfect progressive
Future
Etymology
Origin of knock
First recorded before 1000; 1890–95 knock for def. 4; Middle English knokken, knoken (verb), Old English cnocian, cnucian; cognate with Old Norse knoka “to thump, knock”
Explanation
When you knock, you bump or strike someone or something. When you hear a knock at the door, someone on the other side is thumping it with their knuckles. You can accidentally knock your grandmother's special glass bowl off the table, and you can also knock softly on her door — or tap with your knuckles — before you go in and tell her how sorry you are. If a car engine knocks, it makes a rattling or rapping sound. Colloquially, to knock something is to reject or criticize it, and if you do, you may hear the phrase, "Don't knock it until you try it!"
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Friday's knock at Old Trafford came against a Durham side featuring Ben Stokes.
From BBC ● Aug. 15, 2026
But within a week of settling down, she’d receive a knock on her door, step out of her home, and see flames burning a nearby hillside.
From Los Angeles Times ● Aug. 14, 2026
The knock on such megamergers is well-known: They distract management, sow years of organizational chaos, and invite regulatory scrutiny.
From The Wall Street Journal ● Aug. 6, 2026
When these materials slam into Earth's magnetic shield, they can knock out satellites, threaten astronauts -- and create colourful auroras in the skies of northern and southern latitudes.
From Barron's ● Aug. 5, 2026
He could almost sense the black dog waiting for him to knock, and if he did, there was no telling what the dog would do.
From "Chronicles of a Lizard Nobody" by Patrick Ness
"It brings so much emotion back that it really knocks you for six and you go into a really deep depression."
From BBC ● Aug. 10, 2026
"When someone knocks on your door and tells you: 'Get up, come on, leave here. This is real, you have to go.'"
From Barron's ● Jul. 11, 2026
“I feel responsible for what happened,” the neighbor said, adding that the knocks on Marseille’s door sounded “hostile.”
From Los Angeles Times ● Jun. 20, 2026
The standard homestead exemption knocks $2,000 off the assessed value of all primary residences.
From MarketWatch ● Jun. 15, 2026
She rings the doorbell a dozen times, alternating with a series of loud knocks, though she can hear the bell echoing within the house.
From "The Night Circus" by Erin Morgenstern
A second pulse containing high-energy photons then knocked electrons out of the material.
From Science Daily ● Aug. 20, 2026
You can't get knocked out in a heat and go home.
From BBC ● Aug. 15, 2026
Some artificial-intelligence stocks that got knocked off their pedestals, in part due to a bruising July selloff, now represent attractive opportunities for investors, according to BofA analysts.
From MarketWatch ● Aug. 14, 2026
Increase in playoffs-related revenue over last year for Madison Square Garden Sports Corp., whose New York Knicks won the NBA championship in June after getting knocked out in the Eastern Conference Finals last year.
From The Wall Street Journal ● Aug. 14, 2026
You could have knocked us over with feathers.
From "The Teacher’s Funeral" by Richard Peck
They'd been knocking on the door for three seasons, under different managers, before he arrived; second, third and second in the three campaigns prior to his elevation from coaching at underage level.
From BBC ● Aug. 17, 2026
“So they’re now all knocking on the door, coming and having the conversations with the team.”
From The Wall Street Journal ● Aug. 13, 2026
In November 2025, Beatriz Ziegenfus told authorities that she was passing the dog and his owner when it lunged at her and bit her on her right forearm, knocking her down.
From Los Angeles Times ● Aug. 13, 2026
As a result, the retailer’s customer traffic and store transactions have fallen below executives’ expectations, squeezing sales and profit and knocking roughly 32% off the stock price this year.
From The Wall Street Journal ● Aug. 10, 2026
But as I return to my seat, I brush against Kumu Whitman’s desk, knocking his old-school tie to the ground.
From "Clairboyance" by Kristiana Kahakauwila
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
