[ nok ]
See synonyms for: knockknocked on

verb (used without object)
  1. 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.

  2. to strike in collision; bump: He knocked into a table.

  1. to make a pounding noise: The engine of our car is knocking badly.

  2. Informal. to engage in trivial or carping criticism; find fault.

  3. 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)
  1. to give a sounding or forcible blow to; hit; strike; beat.

  2. to drive, force, or render by a blow or blows: to knock a man senseless.

  1. to make by striking a blow or blows: to knock a hole in the wall.

  2. to strike (a thing) against something else.

  3. Informal. to criticize, especially in a carping manner: He's always knocking everything.

  4. British Slang. to astound; impress greatly.

  1. an act or instance of knocking.

  2. the sound of knocking, especially a rap, as at a door.

  1. a blow or thump.

  2. Informal. an adverse criticism.

  3. the noise resulting from faulty combustion or from incorrect functioning of some part of an internal-combustion engine.

  4. Cricket. an innings.

  5. British Slang.

    • one of a combination of dealers who bid together, rather than against each other, at an auction, and later resell the purchases among themselves.

    • an auction at which this is done.

    • the sale of merchandise recently obtained by a dealer at an auction.

Verb Phrases
  1. knock around / about Informal.

    • to wander aimlessly or idly; loaf.

    • to mistreat (someone), especially physically.

    • to jar; shake up.

  2. knock back, Slang. to drink (a beverage), especially quickly and heartily: He knocked back two shots of vodka.

  1. knock down,

    • to sell at auction by a blow of the hammer or to a bidder.

    • to take apart or disassemble, as for facility in handling, storing, shipping, etc.

    • Slang. to receive, as a salary or a scholastic grade; earn: He knocks down 30 grand a year.

    • Informal. to lower the price of; reduce: to knock down end-of-season leftovers.

    • Slang. to embezzle or steal (money).

    • to cause (a sailing vessel) to heel, as by a gust of wind, to such a degree that it cannot right itself.

  2. knock off,

    • Informal. to cease activity, especially work: to knock off at five every day.

    • to stop doing something; quit: Knock it off or you'll get into a mess.

    • Slang. to dispose of; finish.

    • Slang. to murder; kill.

    • Slang. to die.

    • Slang. to get rid of; reduce.

    • Slang. to disable or defeat.

    • Slang. to commit a robbery at; steal from: The gang knocked off a gas station.

    • Nautical Slang. to blow the head (of a sailing vessel) off the wind.

    • to imitate, copy, or plagiarize: to knock off designer dresses in cheap materials.

  3. knock out,

    • to defeat (an opponent) in a boxing match by striking such a blow that the opponent is unable to rise within the specified time.

    • to render (a person) unconscious: Those sleeping pills knocked me out for ten hours.

    • to make tired or exhausted: Christmas shopping always knocks me out.

    • Informal. to produce quickly, hurriedly, or with ease: He knocks out two poems a day.

    • to damage or destroy: The explosion knocked out the power for several hours.

  4. knock over,

    • to strike (someone or something) from an erect to a prone position: to knock over a lamp.

    • to distress; overcome: When the announcement came we were completely knocked over.

    • Slang. to rob, burglarize, or hijack: He knocked over five banks.

  5. knock together, to make or construct in a hurry or with little attention to detail: He knocked together a couple of tables.

  6. knock up,

    • Slang. to make pregnant.

    • to exhaust; weary; tire.

    • to damage; mar: The children knocked up the new table.

    • to injure; wound: He was afraid to come home from school all knocked up again.

    • British. to wake up; rouse; call: He knocked us up before dawn.

Idioms about knock

  1. have it knocked, Slang. to be assured of success: With a government job, he thought he had it knocked.

  2. knock out of the box, Baseball. to cause a pitcher to be removed from the box because the pitcher has permitted too many hits to be made.: Also knock out.

  1. knock the / one's socks off, Informal. to have an overwhelming effect on: The song knocked the socks off the audience.

Origin of knock

First recorded before 1000; 1890–95 for def. 4; Middle English knokken, knoken (verb), Old English cnocian, cnucian; cognate with Old Norse knoka “to thump, knock”

synonym study For knock

1. See strike.

Other words from knock

  • knockless, adjective
  • re·knock, verb
  • un·knocked, adjective
  • un·knock·ing, adjective

Words Nearby knock Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use knock in a sentence

British Dictionary definitions for knock


/ (nɒk) /

  1. (tr) to give a blow or push to; strike

  2. (intr) to rap sharply with the knuckles, a hard object, etc, esp to capture attention: to knock at the door

  1. (tr) to make or force by striking: to knock a hole in the wall

  2. (intr usually foll by against) to collide (with)

  3. (tr) to bring into a certain condition by hitting or pushing: to knock someone unconscious

  4. (tr) informal to criticize adversely; belittle: to knock someone's work

  5. Also: pink (intr) (of an internal-combustion engine) to emit a characteristic metallic noise as a result of faulty combustion

  6. (intr) (of a bearing, esp one in an engine) to emit a regular characteristic sound as a result of wear

  7. British slang to have sexual intercourse with (a person)

  8. knock a person into the middle of next week informal to hit a person with a very heavy blow

  9. knock one's head against to have a violent or unpleasant encounter with (adverse facts or circumstances)

  10. knock on the head

    • to daze or kill (a person) by striking on the head

    • effectively to prevent the further development of (a plan)

    • a blow, push, or rap: he gave the table a knock

    • the sound so caused

  1. the sound of knocking in an engine or bearing

  1. informal a misfortune, rebuff, or setback

  2. informal unfavourable criticism

  3. informal (in cricket) an innings or a spell of batting

Origin of knock

Old English cnocian, of imitative origin; related to Old Norse knoka to hit

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Idioms and Phrases with knock


In addition to the idioms beginning with knock

  • knock about
  • knock back
  • knock cold
  • knock dead
  • knock down
  • knock down with a feather
  • knock for a loop
  • knock into a cocked hat
  • knock it off
  • knock off
  • knock oneself out
  • knock on wood
  • knock out
  • knock over
  • knock over with a feather
  • knock someone's block off
  • knock someone's socks off
  • knock the bottom out of
  • knock the living daylights out of
  • knock the socks off
  • knock together
  • knock up

also see:

  • beat (knock) into someone's head
  • beat (knock) the living daylights out of
  • (knock) down to size
  • (knock) off someone's feet
  • school of hard knocks

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.