Word
knock
US/ˈnɑk/
UK/nˈɒk/
Definitions
01to rap on a surface
v. to hit a surface with your knuckles or a hard object to make a sound, usually to get attention.
v. to strike a surface, typically a door, with the knuckles or a knocker to signal one's presence or request entry.
“I had to knock on the door three times before anyone heard me.”
“The courier had to knock repeatedly on the heavy oak door before the receptionist finally emerged from the back office.”
Usage
Often used with the preposition 'on'.
02to hit or bump
v. to hit something by accident, often causing it to move or fall.
v. to strike or collide with something, often resulting in displacement or damage.
“Be careful not to knock that vase off the table with your bag.”
“The cyclist was nearly knocked off his bike when a car door opened suddenly in his path.”
Usage
Frequently used in phrasal verbs like 'knock over' or 'knock down'.
03to criticize
v. to say negative things about something or someone.
v. to criticize or disparage something, often unfairly or habitually.
“Don't knock it until you've tried it; the food is actually quite good.”
“Critics were quick to knock the director's latest film, though audiences seemed to appreciate its unconventional pacing.”
Informal
04a rapping sound
n. the sound made when someone hits a door or surface.
n. the sound produced by a sharp blow or rap against a hard surface.
“There was a loud knock at the door just as we sat down for dinner.”
“A sharp, rhythmic knock echoed through the hallway, startling the residents who were not expecting visitors so late.”
05a setback or blow
n. a difficult experience or a failure that hurts your progress.
n. a figurative blow, setback, or unfortunate experience that affects one's confidence or progress.
“Losing his job was a big knock to his confidence.”
“The company took a serious knock when its main competitor released a cheaper, more efficient version of the same product.”
Informal
Synonyms
06engine noise
n. a metallic sound in a car engine that shows something is wrong.
n. a characteristic metallic sound in an internal combustion engine caused by improper combustion.
“The mechanic said the knock in the engine was caused by low-quality fuel.”
“Persistent engine knock can lead to significant mechanical failure if the timing of the spark ignition is not adjusted immediately.”
Technical
Synonyms
Etymology
From Middle English knokken, from Old English cnocian, ġecnocian, ġecnucian, cnucian (“to knock, pound on, beat”), from Proto-West Germanic knokōn, from Proto-Germanic knukōną (“to knock”), a suffixed form of knu-, knew- (“to pound on, beat”), from Proto-Indo-European gnew-, gen- (“to squeeze, pinch, kink, ball up, concentrate”). The English word is cognate with Middle High German knochen (“to hit”), Old English cnuian, cnuwian (“to pound, knock”), Old Norse knoka (compare Danish knuge (“to squeeze”), Swedish knocka (“to hug”)).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Collocations
Word family
Related words
Idioms
don't knock yourself out — Don't overexert yourself (in doing something that does not require much effort).
knock down a peg — Synonym of take down a notch.
knock for a loop — To astonish; to stagger or overwhelm; to confuse or disorient.
knock on heaven's door — To die or be close to death.
knock on wood — To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement.
knock oneself out — To go ahead; to do as one pleases; to enjoy oneself; to endeavor very hard at a task.
knock out — To strike or render unconscious
knock out of the box — To cause something to be replaced by something else.
knock some sense into — To reprimand or reform someone vigorously.
knock someone down with a feather — Alternative form of knock someone over with a feather.
Show all 20
knock someone flat — To knock someone down; to hit someone so they fall to the floor.
knock someone into the middle of next week — To thoroughly beat or trounce someone.
knock someone off their perch — To defeat or overcome someone who was in a dominant position.
knock someone over with a feather — To greatly surprise or astonish someone.
knock someone's block off — To strike a person in the head, causing them to fall to the ground, especially in an unconscious condition; to beat up a person.
knock someone's socks off — To impress greatly; amaze; stun.
knock the living daylights out of — To beat or strike someone.
knock the stuffing out of — To cause (someone, a team) to lose energy and confidence.
knock together — To assemble something quickly.
school of hard knocks — The source of an education consisting of real-world experiences, especially adverse experiences.