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

The university suspects foul play, and said its Division of Public Safety & Security had been dispatched to investigate.

From The Wall Street Journal ● Jul. 26, 2026

Apple is crying foul, arguing that Micron’s gross profit margins, now surpassing 80%, are evidence of price gouging.

From The Wall Street Journal ● Jul. 25, 2026

It's not the first time the cattle-farming politician has fallen foul of man's best friend -- he once threatened to kill Johnny Depp's dogs.

From Barron's ● Jul. 21, 2026

The sheriff’s department has not been able to determine how the man entered the waterway, but no foul play is suspected at this point.

From Los Angeles Times ● Jul. 16, 2026

Quickly, I planted my feet at the foul line.

From "The Million Dollar Shot" by Dan Gutman

In a shocking first half, Argentina committed more fouls than passes in the final third of the pitch.

From BBC ● Jul. 20, 2026

By the end of the first half, the defending champions had managed zero attempts on goal but committed nine fouls.

From The Wall Street Journal ● Jul. 19, 2026

When fouls are studied like the Zapruder Film, even the slightest contact takes on proportions that countries like Sweden would simply prefer to live without.

From The Wall Street Journal ● Jul. 13, 2026

Does the number of yellows match the number of fouls?

From BBC ● Jul. 8, 2026

So they called technical fouls on four of our players for leaving the bench and on Coach for unsportsmanlike conduct.

From "The Absolutely True Diary of a Part-Time Indian" by Sherman Alexie

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

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

From BBC ● Oct. 18, 2016

Now the OKC point guard is probably in an even fouler mood: On Friday, the team announced he’s having surgery to repair a torn right meniscus and will be out “indefinitely.”

From Slate ● Apr. 26, 2013

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

Stones and dung and fouler things whistled overhead.

From "A Clash of Kings" by George R.R. Martin

Many have experienced its foulest moods and nowadays can even record what they’ve seen on their smartphones, then share the footage online.

From National Geographic ● Dec. 15, 2023

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

In the early 1980s, I bartended at an Edward Gorey exhibit at New York’s Gotham Book Mart, serving some of the foulest red wine known to humankind.

From Seattle Times ● Nov. 23, 2018

I wasn’t above being a big, fat imposter if it diverted attention away from a potential drenching with the world’s foulest substance.

From "The Evolution of Calpurnia Tate" by Jacqueline Kelly

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

Having fouled Florent Malouda for France's opener, the towering defender levelled with a thundering header from Andrea Pirlo's corner inside 20 minutes.

From BBC ● Jul. 17, 2026

Plum fouled out midway through the fourth quarter after being held to four points in the third quarter.

From Los Angeles Times ● Jun. 16, 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

Then, when one of their players got fouled, the coach took out both Glen and Frank, moved Jimmy over to forward, put Jose at center and put Trip at the other forward.

From "Slam!" by Walter Dean Myers

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

Sithole's dismissal for fouling Brian Gutierrez was a simple decision for referee Wilton Sampaio.

From BBC ● Jun. 11, 2026

And after Smart grabbed it and threw up a desperate three... what was Jae’Sean Tate doing fouling him?

From Los Angeles Times ● Apr. 25, 2026

Expecting to see only Count Atlas fouling Seabiscuit, the newspapermen saw that and something more.

From "Seabiscuit: An American Legend" by Laura Hillenbrand

Related Words

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