knock out

2 meanings

Meanings
  1. 1 make someone unconscious, especially by hitting them B2
  2. 2 beat someone so they leave a competition B2
1 knock sb out

make someone unconscious, especially by hitting them

B2

What does "knock out" mean in this sense?

To knock someone out means to hit them hard enough that they lose consciousness — they become unaware of their surroundings and cannot move or respond. This happens most often in combat sports like boxing or MMA, where a powerful punch or blow to the head causes the opponent to fall unconscious. It can also happen in everyday accidents, such as when someone hits their head in a fall. Outside of fighting contexts, substances like strong medication or anaesthesia can also knock someone out, putting them into a deep, unresponsive sleep. The key idea is always that an external force or substance causes another person to lose consciousness — it is not something that happens on its own.

Examples

How to use it

knock + object + out

The most common structure, with the object placed between the verb and particle — especially preferred with short noun phrases and obligatory with pronouns.

She landed a clean punch and knocked her opponent out in the second round.

knock out + long noun phrase

When the object is a long noun phrase, the particle naturally follows the whole phrase rather than splitting it.

The punch knocked out the undefeated local champion who had been favourite to win.

knock + pronoun + out

With pronoun objects, separation is always required — the pronoun must come between 'knock' and 'out'.

He swung hard and knocked him out before the referee could step in.

be knocked out (passive)

The passive form is very natural, especially in sports reporting and news, when the focus is on the person who lost consciousness rather than who caused it.

The challenger was knocked out in the opening round and couldn't get back up.

knocked out cold

This intensified form is used to emphasise that someone was completely unconscious, not just dazed.

He hit the canvas and lay knocked out cold while the referee counted to ten.

Common Collocations

knock out an opponentknock out coldknocked out in the first roundknock someone out with a punchbe knocked out by a blow

Common Mistakes

Wrong pronoun placement

When the object is a pronoun, it must always go between 'knock' and 'out'. Placing a pronoun after the particle is ungrammatical in English.

✗ The punch knocked out him immediately.
✓ The punch knocked him out immediately.
Confusing with 'knock out of' (elimination sense)

'Knock out' (make unconscious) and 'knock out of' (eliminate from a competition) are different meanings. If you add 'of' after the object, it shifts the meaning to elimination from a tournament or contest.

✗ The boxer was knocked out the competition in the semi-final.
✓ Use 'knocked out of the competition' for elimination, and 'knocked out' alone for losing consciousness.
Using 'pass out' and 'knock out' interchangeably

'Pass out' means to lose consciousness on your own (e.g. from heat or shock), while 'knock out' requires someone or something to cause the unconsciousness — it always needs an external cause and a person as the object.

✗ He knocked out from the heat during training.
✓ He passed out from the heat during training. / The blow knocked him out.

Usage

This phrasal verb is neutral in register and works in both spoken and written English. Be careful not to confuse it with 'knock out of', which means to eliminate someone from a competition — both senses are common at B2 level.

2 knock sb out

beat someone so they leave a competition

B2

Sense 2: What does "knock sb out" mean?

To knock someone out of a competition means to beat them so decisively that they can no longer continue and must leave the tournament or contest. It describes the moment when a team or player loses a match in a knockout-style competition — such as a cup or championship — and has no path forward. The phrase is extremely common in sports journalism and everyday conversation, and it works equally well in spoken commentary and written match reports. What makes it distinctive is that the passive form ('were knocked out') is often the most natural choice, since the focus tends to be on the team or player who has been eliminated rather than on who beat them. You can also use it beyond traditional sport — for example, in a quiz competition or a talent show — whenever the idea of being eliminated from a structured contest applies.

Examples

How to use it

knock + object + out of + competition

The most common active structure, naming who was eliminated and from which competition.

A last-minute goal knocked the reigning champions out of the cup.

be knocked out of + competition

The passive form is very natural in sports reporting, especially when the focus is on the team that was eliminated.

France were knocked out of the tournament in the quarter-finals.

knock + pronoun + out

When the object is a pronoun, it must go between 'knock' and 'out' — it cannot follow 'out'.

The underdogs played brilliantly and knocked them out in the first round.

be knocked out + in the [stage]

Use this pattern to specify at which stage of the competition the elimination happened.

The home team were knocked out in the group stage despite a strong start.

knock + object + out + on penalties / by [opponent]

Use these prepositional phrases to explain how or by whom the elimination occurred.

A surprise qualifier knocked out the top seed on penalties to reach the final.

Common Collocations

knocked out of the tournamentknocked out of the World Cupknocked out in the quarter-finalsknocked out by the favouritesknocked out on penaltiesknocked out in the first round

Common Mistakes

Wrong preposition after 'out'

Learners often write 'knocked out from the tournament' or 'knocked out the tournament' (with no preposition at all). The correct preposition is always 'of': 'knocked out of the tournament'.

✗ They were knocked out from the championship in the semi-finals.
✓ They were knocked out of the championship in the semi-finals.
Pronoun placed in the wrong position

When the object is a pronoun such as 'them', 'us', or 'him', it must go between 'knock' and 'out'. Placing it after 'out' is incorrect.

✗ The hosts knocked out them in the opening round.
✓ The hosts knocked them out in the opening round.
Confusing the competition sense with the physical sense

In sports and contest contexts, 'knock out' means to eliminate from a competition — not to render someone unconscious as in boxing. Context usually makes this clear, but learners should be aware the same form has a completely different meaning in a physical or medical situation.

Usage

This phrasal verb is neutral and works equally well in spoken and written sports contexts. In British English, it is very common to say 'they were knocked out' using the passive — this is often more natural than the active form.

Frequently Asked Questions

Can 'knock out' be used for things other than punches — like a fall or medication?

Yes — any force or substance that causes someone to lose consciousness can be the subject. A fall, a collision, or even strong anaesthesia can knock someone out. For example: 'The sleeping pills knocked him out within minutes.' The essential idea is that something external causes the loss of consciousness.

Does 'knocked out' always describe the moment someone loses consciousness, or can it describe the state afterwards?

Both are possible. 'Knocked him out' describes the action (the moment it happened), while 'he was knocked out' or 'he lay knocked out' describes the resulting state. The past participle form works naturally as an adjective to describe someone who is unconscious.

Can I say 'he is being knocked out' in the present continuous?

This sounds awkward in most situations because losing consciousness is typically an instantaneous event, not a gradual process. It's more natural to use the simple present for commentary ('He knocks him out!') or the simple past for describing what happened ('He knocked him out'). The present continuous is best avoided with this sense.

Does 'knock out' have other meanings I should know about?

Yes — the same verb and particle combination has several other meanings in English, including eliminating someone from a competition and producing something quickly. This page covers only the 'make unconscious' sense. A good clue for this specific sense is that the object is always a person or creature who loses consciousness due to a physical blow or substance.

Does 'knock out' have other meanings, or does it always mean eliminating someone from a competition?

This phrasal verb has several different meanings depending on context. On this page, we focus only on the competition sense — meaning a team or player can no longer continue in a tournament. Other senses of 'knock out' are covered separately on this platform.

In British English, should I say 'Germany were knocked out' or 'Germany was knocked out'?

In British English, team names and country names used to represent a team are treated as plural, so 'Germany were knocked out' is standard. In American English, the singular form 'Germany was knocked out' is more typical. Both are correct — it depends on which variety of English you are using or learning.

Is it natural to use 'knock out' in the active form, or should I always use the passive?

Both are natural, but the passive ('were knocked out') dominates in sports reporting because the focus is usually on the losing side. The active form ('Spain knocked out Portugal') is perfectly correct and is often used when you want to emphasise the winning team's performance or achievement.

Can I use 'knock out' to talk about non-sporting competitions, like a TV talent show?

Yes — 'knock out' works well in any elimination-style contest where a competitor can no longer continue. For example, 'She was knocked out of the singing competition in the second round' is completely natural. The key idea is a structured competition with rounds, not just any defeat.

Do I always need to mention which competition someone was knocked out of?

Not always — if the competition is already clear from context, you can leave it out. For example, if you are already discussing the World Cup, saying 'they were knocked out in the semi-finals' is perfectly natural without repeating the competition name.

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