knock out

Short definition: The phrase knock out means to make someone unconscious by hitting them, or to defeat someone decisively, often used in sports or competitions.

Looking for a clear and natural explanation of the phrasal verb knock out? This expression appears frequently in both everyday conversation and sports contexts. It can describe making someone unconscious with a strong hit, eliminating someone from a competition, destroying something, or even impressing people strongly in informal language. Because it has both literal and figurative meanings, the exact sense depends on the situation in which it is used. Below are detailed meanings with realistic examples so you can clearly understand how knock out works in everyday English.

knock out v. /ˌnɒk ˈaʊt/

Forms: knock out, knocks out, knocked out, knocking out
Related: defeat v., eliminate v., stun v., destroy v.
Syllable: knock-out

(Verb) To make someone unconscious with a strong hit.
To knock out most commonly means hitting someone so hard that they lose consciousness for a short time, which is often described in sports like boxing or in dramatic situations.

The boxer knocked out his opponent in the third round of the match.

One powerful punch was enough to knock him out instantly.

The fighter tried to avoid getting knocked out by staying on the defensive.

Synonyms: render unconscious, stun, flatten, floor, strike down, overpower, drop with a blow, put to sleep, hit unconscious, strike senseless, incapacitate, disable
Antonyms: revive, awaken, regain consciousness, stand up, recover, recover awareness, wake up, regain balance, stay conscious, recover quickly, come around, rise again
(Verb) To eliminate someone from a competition or contest.
In sports or tournaments, knock out means defeating a competitor so that they can no longer continue in the competition.

The underdog team knocked out the champions in the quarterfinals.

Several strong teams were knocked out early in the tournament.

Their victory knocked out the rival club from the playoffs.

Synonyms: eliminate, defeat, remove from contest, beat decisively, push out, eliminate from tournament, remove competitor, disqualify, overcome, dominate, outplay, knock from race
Antonyms: advance, qualify, win through, remain in contest, survive round, move forward, continue competing, stay in tournament, progress, reach next stage, triumph, proceed
(Verb) To destroy or disable something completely.
Knock out can also mean damaging or disabling something so that it stops working or functioning properly.

The storm knocked out power in several neighborhoods.

The explosion knocked out the communication system.

The strong wind knocked out a few windows in the building.

Synonyms: destroy, disable, shut down, break, damage severely, wipe out, ruin, put out of action, smash, demolish, disrupt completely, collapse
Antonyms: repair, restore, fix, rebuild, reactivate, restart, recover system, maintain function, repair damage, bring back online, rebuild structure, restore operation
(Verb) To impress someone greatly or make a very strong positive impression.
In informal English, knock out can describe something that impresses people strongly, especially because it looks amazing or performs extremely well.

Her performance completely knocked out the audience.

That new design will really knock people out.

The singer’s voice absolutely knocked out the judges.

Synonyms: impress greatly, amaze, astonish, wow, stun positively, captivate, overwhelm with talent, delight strongly, dazzle, blow away, thrill audience, charm deeply
Antonyms: disappoint, bore, underwhelm, fail to impress, dull reaction, lose interest, frustrate, let down, unimpress, discourage, displease, fall flat

Conversation Using the Phrasal Verb Knock out

At a sports center, Arthur and Beatrice are discussing a recent boxing match and other events. This conversation highlights knock out, which means to make someone unconscious, to defeat a team in a competition, or to complete a task very quickly.

Arthur: Did you see the fight last night? The champion managed to knock out his opponent in the very first round!

Beatrice: It was incredible; I didn't expect him to knock out such a strong challenger so early in the match.

Arthur: I read that the underdog team was able to knock out the favorites during the quarter-finals of the national tournament.

Beatrice: I noticed that the strong medication the doctor gave me managed to knock out my headache in less than twenty minutes.

Arthur: If we work together this afternoon, we can knock out the remaining reports before the office closes for the weekend.

Beatrice: I saw a beautiful sunset that was so stunning it almost managed to knock out all the stress I had felt during the day.

Arthur: It’s a tragedy when a single mistake can knock out a company’s entire server system and cause hours of expensive downtime.

Beatrice: I agree; I’m going to knock out these last few emails so I can finally relax and enjoy my evening without any more work.

Arthur: I’m glad we could knock out the cleaning so fast; the house looks wonderful and we still have the whole afternoon to ourselves.

Beatrice: Me too; once we knock out the grocery shopping, we’ll be completely prepared for the dinner party tomorrow night.

Phrases Containing the Phrasal Verb Knock Out

The phrases below show how the phrasal verb knock out is used to talk about defeating, making someone unconscious, or removing something forcefully.

Knock out an opponent

To defeat someone in a fight.

The boxer managed to knock out his opponent in the final round of the match.

Knock out cold

To make someone unconscious.

The strong impact knocked him out cold for several minutes.

Knock out of the competition

To eliminate from a contest.

The defending champion was knocked out of the competition earlier than expected.

Knock out a tooth

To remove a tooth by force.

The accident nearly knocked out a tooth, but fortunately it was saved.

Knock out power

To cause a power outage.

The storm knocked out power across several neighborhoods.

Knock out the lights

To turn off electricity suddenly.

The lightning strike knocked out the lights during the event.

Knock out a rival

To defeat a competitor.

The company launched a new product to knock out a rival brand.

Knock out in the first round

To defeat quickly.

The fighter shocked the audience by knocking out his opponent in the first round.

Knock out a candidate

To eliminate from consideration.

The difficult interview questions knocked out several candidates early.

Knock out production

To complete quickly (informal).

The team managed to knock out production tasks faster than expected.

Knock out a wall

To remove a structure forcefully.

They decided to knock out a wall to create more space in the living room.

Knock out a punch

To deliver a strong hit.

He knocked out a powerful punch that ended the match dramatically.

Knock out of shape

To damage structure.

The collision knocked the vehicle out of shape.

Knock out a competitor

To eliminate in business.

The new pricing strategy was designed to knock out a competitor from the market.

Knock out the opposition

To defeat completely.

The team aimed to knock out the opposition and secure a place in the finals.

Knock out a player

To eliminate from a game.

One mistake can knock out a player in this intense tournament.

Knock out energy

To exhaust someone.

The long journey knocked out all his energy.

Knock out a target

To hit successfully.

The skilled archer knocked out the target with remarkable precision.

Knock out completely

To eliminate entirely.

The strong medication knocked him out completely for several hours.

Knock out unexpectedly

To defeat surprisingly.

The underdog team knocked out the champions unexpectedly.

Words Rhyme with knock out

shock out

block out

dock out

lock out

rock out

stock out

clock out

mock out

crock out

flock out

out

about

shout

scout

doubt

trout

bout

snout

gout

route

spout

stout

clout

flout

without

throughout

devout

redoubt

dropout

turnout

POS: Verb Phrase, Noun Phrase