foul

American  

[foul] / faʊl /

adjective

• fouler,
  comparative
• foulest
  superlative

1. grossly offensive to the senses; disgustingly loathsome; noisome.

   a foul smell.

   Synonyms:

   repellent, repulsive

   Antonyms:

   pleasant

2. containing or characterized by offensive or noisome matter.

   foul air; foul stagnant water.

   Synonyms:

   stinking, putrid, fetid

3. filthy or dirty, as places, receptacles, clothes, etc.

   Synonyms:

   impure, polluted, unclean

   Antonyms:

   clean

4. muddy, as a road.

5. clogged or obstructed with foreign matter.

   a foul gas jet.

   Antonyms:

   clear

6. unfavorable or stormy.

   foul weather.

   Synonyms:

   tempestuous, rainy

   Antonyms:

   clear

7. contrary, violent, or unfavorable, as the wind.

   Synonyms:

   adverse

8. grossly offensive in a moral sense.

9. abominable, wicked, or vile, as deeds, crime, slander, etc.

   Synonyms:

   infamous, shameful, base

10. scurrilous, profane, or obscene; offensive.

    foul language.

    Synonyms:

    low, coarse, vulgar, smutty

11. contrary to the rules or established usages, as of a sport or game; unfair.

    a foul blow.

12. Baseball. pertaining to a foul ball or a foul line.

13. limited in freedom of movement by obstruction, entanglement, etc..

    a foul anchor.

14. abounding in errors or in marks of correction, as a printer's proof, manuscript, or the like.

15. Nautical.

    1. (of the underwater portion of a hull) encrusted and impeded with barnacles, seaweed, etc.

    2. (of a mooring place) involving inconveniences and dangers, as of colliding with vessels or other objects when swinging with the tide.

    3. (of the bottom of a body of water) affording a poor hold for an anchor (opposed to clean).

16. North England and Scot.. not fair; ugly or unattractive.

17. Obsolete. disfigured.

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adverb

1. in a foul manner; vilely; unfairly.

2. Baseball. into foul territory; so as to be foul.

   It looked like a homer when he hit it, but it went foul.

noun

• fouls
  plural

1. something that is foul.

2. a collision or entanglement.

   a foul between two racing sculls.

3. a violation of the rules of a sport or game.

   The referee called it a foul.

4. Baseball. foul ball.

verb (used with object)

• fouls,
  present (3rd person singular)
• fouled,
  past participle,  past
• fouling
  present participle

1. to make foul; defile; soil.

   Synonyms:

   pollute, taint, besmirch, dirty, stain, sully

   Antonyms:

   clean

2. to clog or obstruct, as a chimney or the bore of a gun.

3. to collide with.

4. to cause to become entangled or caught, as a rope.

5. to defile; dishonor; disgrace.

   His reputation had been fouled by unfounded accusations.

   Synonyms:

   shame

6. Nautical. (of barnacles, seaweed, etc.) to cling to (a hull) so as to encumber.

7. Baseball. to hit (a pitched ball) foul (often followed by off oraway ).

   He fouled off two curves before being struck out on a fastball.

verb (used without object)

• fouls,
  present (3rd person singular)
• fouled,
  past participle,  past
• fouling
  present participle

1. to become foul.

2. Nautical. to come into collision, as two boats.

3. to become entangled or clogged.

   The rope fouled.

4. Sports. to make a foul play; give a foul blow.

5. Baseball. to hit a foul ball.

verb phrase

1. foul up to cause confusion or disorder; bungle; spoil.

2. foul out

   1. Baseball. to be put out by hitting a foul ball caught on the fly by a player on the opposing team.

   2. Basketball. to be expelled from a game for having committed more fouls than is allowed.

idioms

1. run foul / afoul of, to come into collision or controversy with.

   to run foul of the press.

2. foul one's nest, to dishonor one's own home, family, or the like.

3. fall foul / afoul of,

   1. to collide with, as ships.

   2. to come into conflict with; quarrel.

   3. to make an attack; assault.

foul British  

/ faʊl /

adjective

1. offensive to the senses; revolting

2. offensive in odour; stinking

3. charged with or full of dirt or offensive matter; filthy

4. (of food) putrid; rotten

5. morally or spiritually offensive; wicked; vile

6. obscene; vulgar

   foul language

7. not in accordance with accepted standards or established rules; unfair

   to resort to foul means

8. (esp of weather) unpleasant or adverse

9. blocked or obstructed with dirt or foreign matter

   a foul drain

10. entangled or impeded

    a foul anchor

11. (of the bottom of a vessel) covered with barnacles and other growth that slow forward motion

12. informal unsatisfactory or uninteresting; bad

    a foul book

13. archaic ugly

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noun

1. sport

   1. a violation of the rules

   2. ( as modifier )

      a foul shot

      a foul blow

2. something foul

3. an entanglement or collision, esp in sailing or fishing

verb

1. to make or become dirty or polluted

2. to become or cause to become entangled or snarled

3. (tr) to disgrace or dishonour

4. to become or cause to become clogged or choked

5. (tr) nautical (of underwater growth) to cling to (the bottom of a vessel) so as to slow its motion

6. (tr) sport to commit a foul against (an opponent)

7. (tr) baseball to hit (a ball) in an illegal manner

8. (intr) sport to infringe the rules

9. (tr) (of an animal, especially a dog) to defecate on

   do not let your dog foul the footpath

10. to collide with (a boat, etc)

adverb

1. in a foul or unfair manner

2. 1. to come into conflict with

   2. nautical to come into collision with

foul More Idioms  

More idioms and phrases containing foul

• run afoul of

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Synonym Usage

See dirty.

Other Word Forms

Derived Forms

• overfoulness
  noun
• overfoul
  adjective
• unfoul
  adjective
• unfouled
  adjective
• foully
  adverb
• overfoully
  adverb
• unfoully
  adverb

Inflected Forms

Nouns

• fouls
  plural

Adjectives

• fouler
  comparative
• foulest
  superlative

Participles

• fouling
  present
• fouled
  past

Conjugated Forms

Present

• foul
  simple
• fouls
  simple
• have fouled
  perfect
• has fouled
  perfect
• am fouling
  progressive
• are fouling
  progressive
• is fouling
  progressive
• have been fouling
  perfect progressive
• has been fouling
  perfect progressive

Past

• fouled
  simple
• had fouled
  perfect
• was fouling
  progressive
• were fouling
  progressive
• had been fouling
  perfect progressive

Future

• will foul
  simple
• will have fouled
  perfect
• will be fouling
  progressive
• will have been fouling
  perfect progressive

Etymology

Origin of foul

before 900; (adj. and noun) Middle English ful, foul, Old English fūl; cognate with Gothic fuls, Old Norse fūll, Old High German fūl; akin to Latin pūs pus, pūtēre to stink, Greek pýon pus; (adv.) Middle English fule, foule, derivative of the adj.; (v.) Middle English fulen, derivative of the adj.

Explanation

Foul is most commonly used as an adjective to describe a bad smell. As a verb, foul usually means “make dirty or messy.” You might foul your room to the point where it smells a bit foul. In general, foul can be used as an adjective meaning "bad." Foul luck is bad luck; a foul day is a bad day. As a verb, foul can mean "break the rules." It’s used this way in sports, like when you commit a foul on the basketball court. The phrase "foul play" can be used in the context of sports or more generally, to indicate unfair or violent behavior. Avoid confusing foul with fowl, which refers to birds, especially chickens.

Example Sentences

See Examples For:

foul fouls fouler foulest fouled fouling

Bass acknowledged foul odors and pest infestations continue to plague residents, and noted she was most concerned for Los Angeles students returning to school next week.

From Los Angeles Times ● Aug. 5, 2026

Five days earlier Ronaldo had been given a red card and a three-game suspension for a serious foul, a penalty that would have forced him to miss the start of the World Cup.

From Los Angeles Times ● Aug. 4, 2026

A post-mortem examination is under way and toxicology tests to determine the cause of death could help confirm if foul play was involved.

From BBC ● Aug. 1, 2026

"He never cried foul, never claimed he was uninformed or pressured, and never suggested there were problems with the discovery materials he and his counsel had reviewed for two years that should have been challenged."

From BBC ● Jul. 28, 2026

Mr. lanucci was nice enough to let me use the gym anytime I wanted, so I could practice my foul shooting.

From "The Million Dollar Shot" by Dan Gutman

"When you watch the previous fights of England their boxers create a lot of fouls," he said.

From BBC ● Jul. 29, 2026

Argentina’s physical approach, which saw them finish with all those fouls and zero shots on target, didn’t win them many friends.

From The Wall Street Journal ● Jul. 21, 2026

Brink, the only natural center on the team, averages just 17.5 minutes per game primarily because of her 3.7 fouls.

From Los Angeles Times ● Jul. 12, 2026

The team also committed 13 fouls to frustrate France and break up the flow.

From The Wall Street Journal ● Jul. 9, 2026

But the ref wasn’t calling touch fouls and Nick and Trip were helping out anytime Ice went up in the air and brought the ball back down.

From "Slam!" by Walter Dean Myers

Having inured himself to the fouler demands of his job, Jovan must now contend with a more depraved, bleach-resistant form of refuse as a rogue insider splatters his workplace with sinister graffiti.

From New York Times ● Nov. 22, 2017

And his merchants and armies were making a befouled realm even fouler.

From Slate ● Feb. 6, 2017

"Foul as it is, Hell itself is made fouler by the presence of John."

From BBC ● Oct. 18, 2016

Those off-flavors are the result of breaking down secondary products like amino acids and the ethanol which might result in some fouler or vinegary compounds, such as esters and aldehydes.

From Scientific American ● Aug. 20, 2012

There are few things fouler than watching huge white maggots writhe inside jars of apricot syrup.

From "City of the Plague God" by Sarwat Chadda

In his first speech to Parliament, the Liberal prime minister defended the rights of plantation owners, but later branded slavery the "foulest crime" in history.

From BBC ● Aug. 25, 2023

“There is no greater fool than one who shouts ‘Happy Christmas!’ in a city throughout which the foulest of mankind lurks ’round every corner,” Holmes growls.

From New York Times ● Dec. 1, 2021

The greatest leader of our time has been struck down by the foulest deed of our time … No words are sad enough to express our sense of loss.

From National Geographic ● Jan. 19, 2021

Now imagine Lennon has steered your ship safely through a horrific storm, lashing himself to the captain’s chair and singing “the foulest, filthiest, manliest sea shanty” through the night.

From Washington Post ● Dec. 21, 2018

That M. Dupont's arrived in the foulest mood imaginable.

From "The Remains of the Day" by Kazuo Ishiguro

It was the law of the blocked road and the fouled well—a pig loose on the highway, a tannery poisoning a shared stream, gunpowder stored where it might ignite and level the block.

From The Wall Street Journal ● Jul. 19, 2026

The spot-kick was awarded in the ninth minute after Luka Modric fouled Noni Madueke.

From BBC ● Jun. 17, 2026

With 40.9 seconds left in the game, Marcus Smart scored, was fouled and made the free throw for a 110-109 Lakers lead.

From Los Angeles Times ● May 12, 2026

Mitchell scored, was fouled by Smart and made the free throw for a three-point play and a 95-92 Thunder lead.

From Los Angeles Times ● May 12, 2026

After the expedition, Neal Beidleman pointed out that if Andy’s regulator had become fouled with ice, the gauge might have registered empty even though the canisters were full, which would explain his bizarre obstinacy.

From "Into Thin Air" by Jon Krakauer

Adrien Rabiot: Lucky to stay on the pitch after fouling Ruiz having already been booked for an early challenge on Dani Olmo.

From BBC ● Jul. 14, 2026

For days before their brutal and bloody round-of-16 match against Paraguay, they devoted hours of practice time to countering soccer’s Dark Arts—trash talk, persistent fouling, and relentless physicality.

From The Wall Street Journal ● Jul. 9, 2026

But the victory came with an asterisk: Folarin Balogun, a Brooklyn-born striker who leads the team in goals, got a red card for fouling an opposing player.

From Slate ● Jul. 6, 2026

That’s because a large portion of the pollution fouling waterways comes from these businesses.

From Los Angeles Times ● Jun. 5, 2026

Rabbits will not excrete underground and Kehaar’s habit of fouling his own nest had always disgusted Hazel.

From "Watership Down: A Novel" by Richard Adams

Related Words

• fetid
• filthy
• hateful
• horrid
• nasty
• putrid
• rotten
• vicious
• vile
• wicked