foul

foul — adjective

1. having a very bad smell, taste, or general quality that makes people feel sick o

1.adjectiveB1
Definition

having a very bad smell, taste, or general quality that makes people feel sick or want to avoid it.

Example

The milk in the fridge gave off a foul smell after sitting for days.

foul smell — very bad odor

After the storm, the basement filled with foul water that smelled like rotten eggs.

Common collocations
  • foul smell
  • foul taste
  • foul odor
  • foul weather
  • foul air
Synonyms
  • disgusting

    more common in everyday speech, same intensity

  • nasty

    slightly less strong, often used for tastes and smells

  • revolting

    stronger, suggests physical sickness

  • putrid

    specifically describes rotting organic matter

Antonyms
  • pleasant

    the opposite for smells, tastes, and weather

  • fresh

    opposite for smells and food

Usage Note

Commonly used with nouns describing sensory experiences such as 'smell', 'taste', 'odour', and 'weather'.

Common Mistakes

The smell was very foully.
The smell was very foul.
'foul' is an adjective, not an adverb; 'foully' is the adverb form and does not work after 'was'.

2. containing rude, obscene, or socially unacceptable words and expressions that ar

2.adjectiveB2
Definition

containing rude, obscene, or socially unacceptable words and expressions that are likely to offend people.

Example

The coach used foul language when arguing with the referee and received a warning.

foul language — rude, swearing words

Ava told her little brother not to repeat the foul words he heard on television.

Common collocations
  • foul language
  • foul mouth
  • foul words
  • foul speech
  • foul talk
Synonyms
  • obscene

    more formal and stronger; implies sexual content

  • vulgar

    focuses on lack of refinement rather than offensiveness

  • profane

    specifically involves religious irreverence

  • crude

    less strong, suggests rudeness rather than obscenity

Antonyms
  • polite

    opposite in social conduct

  • clean

    opposite specifically for language

Usage Note

Usually placed before nouns such as 'language', 'speech', 'mouth', 'words', or 'remarks'. Not used to describe visual obscenity (use 'obscene' or 'indecent' instead).

Common Mistakes

He spoke foul.
He used foul language.
'foul' alone does not describe speech; pair it with 'language', 'words', or 'talk'.

3. describing an action in a sport that the official rules do not allow and that us

3.adjectiveB1
Definition

describing an action in a sport that the official rules do not allow and that usually results in a penalty for the player or team.

Example

The basketball player received a foul warning after pushing his opponent to the ground.

foul (adj.) — describing an illegal move in sports

A foul throw in soccer gives the other team a free kick from that spot.

Common collocations
  • foul tackle
  • foul play
  • foul ball
  • foul throw
  • foul hit
Synonyms
  • illegal

    broader term used in any rule-based activity

  • unfair

    focuses on the spirit of the game, not just written rules

Antonyms
  • legal

    within the rules

  • fair

    in accordance with the rules

Usage Note

In sports contexts, 'foul' can be both an adjective (a foul tackle) and a noun (he committed a foul). The adjective form describes the nature of the action itself.

4. wrong according to moral rules, especially because it involves dishonest, cruel,

4.adjectiveB2
Definition

wrong according to moral rules, especially because it involves dishonest, cruel, or harmful actions that most people would consider bad.

Example

The company used foul means to steal trade secrets from its competitor.

foul means — dishonest methods

Many people consider cheating the elderly out of their savings a foul act.

Common collocations
  • foul means
  • foul deed
  • foul crime
  • foul act
  • foul practice
Synonyms
  • evil

    stronger; implies deliberate intent to harm

  • corrupt

    focuses on dishonesty in positions of power

  • wicked

    similar intensity, more common in storytelling

  • vile

    suggests extreme moral depravity

Antonyms

Usage Note

More formal and literary than other senses of 'foul'. Often appears in fixed phrases such as 'by fair means or foul' (idiom) and 'foul deed'. Less common in everyday conversation; 'evil' or 'corrupt' are more frequent alternatives.

Common Mistakes

He committed a foul crime.' (ambiguous — could mean sports or morality)
He committed a terrible crime.
reserve 'foul crime' for literary or formal contexts where the moral dimension is clear.
Phrasal verbs

foul up

phrasal verb

to spoil or ruin something by making mistakes or handling it badly; to do a task poorly.

The new intern fouled up the order by entering the wrong customer address.

Tomás fouled up his chances of getting the job by arriving late to the interview.

Idioms

criminal or dishonest activity, especially violence that leads to someone being harmed or killed.

The police found no signs of foul play and closed the case as an accident.

When the money went missing, the company suspected foul play among the staff.

using any method possible, whether honest or dishonest, in order to achieve a goal.

The politician was determined to win the election by fair means or foul.

Owen wanted the promotion by fair means or foul, even if it meant lying.

to get into trouble with a person, group, or organization because of doing something wrong or against their rules.

The journalist fell foul of the government after publishing the secret report.

Lakshmi fell foul of the school rules when she copied answers from a friend.

to complain publicly that something is unfair or that someone has acted dishonestly.

The losing team cried foul, claiming the referee had helped their opponents.

When the contract was given to a friend of the boss, the other workers cried foul.

To do something that causes a person or organization to be angry or to punish you.

Mina fell foul of the school principal after skipping class.

Did the company fall foul of environmental regulations?

foul — noun

foul — verb

foul — adverb

Word family

  • foully
    adverbC1
  • foulness
    nounC1
  • fouler
    nounC1

Synonym discussion

Sense: adjective/1

All four words describe something extremely unpleasant to the senses, but they differ in intensity and specific use. 'Foul' is the broadest of the group — it covers bad smells, tastes, weather, and even moral decay. 'Disgusting' is the most common everyday alternative and works for both physical and behavioural contexts ('a disgusting habit'). 'Nasty' is slightly milder and often implies something unpleasant in a less dramatic way ('a nasty cold', 'nasty weather'). 'Revolting' is stronger than 'foul'; it suggests that something makes you feel physically sick or want to turn away. 'Putrid' is the most specific — it only applies to things that are rotting or decomposing ('putrid meat', 'putrid water'). For a learner, 'disgusting' and 'nasty' are the safest everyday choices; 'foul' sits between them in formality; 'revolting' and 'putrid' are for stronger or more specific descriptions.

disgustingnastyrevoltingputrid

Common collocations

Nouns

  • play
  • language
  • smell
  • taste
  • weather
  • means
  • ball
  • tackle
  • shot
  • crime
  • deed

Adverbs

  • foully

Phrases

  • by fair means or foul
  • fall foul of
  • cry foul
  • through foul and fair

Prepositions

  • for
  • on
  • against

Etymology

Proto-Indo-EuropeanProto-GermanicOld EnglishEnglish

The word 'foul' comes from Old English 'fūl', which meant 'dirty, rotten, or corrupt'. It can be traced back to the Proto-Germanic word '*fūlaz' and further to the Proto-Indo-European root '*pū-', meaning 'to rot or decay'. This same ancient root gave rise to related words in other languages, such as Latin 'putere' (to stink) and 'putridus' (rotten), from which English later borrowed 'putrid' and 'putrefy'. The word has carried its core meaning of 'unclean, rotten, offensive' for well over a thousand years, though it gradually developed specific sports senses in the 18th–19th centuries as modern ball games were codified.