knock

1 of 2

verb

ˈnäk 

knocked; knocking; knocks

intransitive verb

1

: to strike something with a sharp blow

2

: to collide with something

3

a

: bustle

heard them knocking around in the kitchen

b

: wander

knocked about Europe all summer

4

a

: to make a pounding noise

b

: to have engine knock

5

: to find fault

transitive verb

1

a(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

see also knock cold, knock dead, knock for a loop, knock one's socks off, knock on wood, knock together

knock

2 of 2

noun

1

a

: a sharp blow : rap, hit

a loud knock on the door

b(1)

: a severe misfortune or hardship

(2)

: setback, reversal

2

a

: 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

Synonyms of knock

Verb

• bump
• bang
• slam
• smash
• collide
• hit
• crash

Noun

• blow
• hit
• thump
• slap
• punch
• whack
• thud
• swipe
• pound
• stroke
• smack
• poke
• bang
• lick
• slam
• beat
• spank

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.

Recent Examples on the Web

Verb

The Sullys learned this the hard way in The Way of Water, and this story doesn't shy away from the necessity of an armed revolution when an ontological evil comes knocking. —Fran Ruiz, Space.com, 19 Dec. 2025

But after United returned home from knocking Red Star Belgrade out of the European Cup, the team’s plane crashed on its third attempt to take off after re-fueling in Germany. —Ben Church, CNN Money, 19 Dec. 2025

Noun

Meanwhile, Marcy Lewis, 75, of Madeira, Ohio, had been wanting a robot vacuum cleaner and deliberately chose a knock-off. —Kevin Williams, CNBC, 20 Dec. 2025

Studio films play theatrically in over 70 countries, then in knock-on markets for decades. —Joseph M. Singer, Deadline, 19 Dec. 2025

Word History

Etymology

Verb

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

First Known Use

Verb

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

Noun

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

Phrases Containing knock

• anti-knock
• don't knock it until you've tried it
• hard-knock
• hit/knock (someone) for six
• knock around
• knock back
• knock/blow someone's socks off
• knock down
• knock-down-and-drag-out
• knock-down, drag-out
• knock heads
• knock in
• knock it out of the park
• knock-knee
• knock-knock joke
• knock off
• knock on doors
• knock-on effect
• knock oneself out
• knock on the door of
• knock out
• knock over
• knock someone flying
• knock (someone) off his/her pedestal
• knock someone's head/block off
• knock (someone) sideways
• knock some sense into someone
• knock some sense into someone's head
• knock (something) on the head
• knock spots off
• knock the stuffing out of
• knock the wind out of (someone)
• knock up
• take/knock/bring someone down a peg
• throw/knock (someone) off (his/her) stride

Rhymes for knock

• balk
• baulk
• bloc
• bock
• broch
• brock
• calk
• caulk
• chalk
• chock
• clock
• cock

Kids Definition

knock

1 of 2 verb

ˈnäk 

1

a

: to strike with a sharp blow

b

: to set in motion with a sharp blow

2

: to bump against something

3

: wander sense 1

knocked about the country last summer

4

: to have engine knock

5

: to find fault with

don't knock it—there are worse jobs

knock

2 of 2 noun

1

: a sharp blow

2

: a severe misfortune or hardship

3

a

: a pounding noise

heard a knock on the door

b

: a sharp rattling noise caused by abnormal ignition in an automobile engine

Medical Definition

knock

noun

ˈnäk 

1

: a sharp blow

a knock to the head

2

: a sharp pounding noise