foul

1 of 4

adjective

ˈfau̇(-ə)l 

1

a

: offensive to the senses : loathsome

the foul odor of rotten eggs

b

: filled or covered with offensive matter

foul bins of filth

2

: being odorous and impure : polluted

foul air

3

a

: morally or spiritually odious : detestable

a foul crime

b

: notably unpleasant or distressing : wretched, horrid

in a foul mood

4

: obscene, abusive

foul language

5

a

: being wet and stormy

foul weather

b

: obstructive to navigation

a foul tide

6

a

: treacherous, dishonorable

fair means or foul

b

: constituting an infringement (see infringe sense 1) of rules in a game or sport

a foul blow in boxing

7

: being outside the foul lines in baseball

… a foul fly that was snagged by a fan in the stands.

—E. M. Swift

8

: containing marked-up corrections

a foul manuscript

foul proofs

9

: full of dirt or mud

10

: encrusted, clogged, or choked with a foreign substance

the chimney was foul and smoked badly

11

: placed in a situation that impedes physical movement : entangled

a foul fishing line

12

dialectal British : homely, ugly

foully

ˈfau̇(l)-lē 

adverb

foulness noun

foul

2 of 4

noun

1

a

: an infringement of the rules in a game or sport

b

: free throw

2

: foul ball

3

: an entanglement or collision especially in angling or sailing

4

archaic : something foul

foul

3 of 4

verb

fouled; fouling; fouls

transitive verb

1

: to make foul: such as

a

: to make dirty : pollute

b

: to tangle or come into collision with

c

: to encrust with a foreign substance

a ship's bottom fouled with barnacles

d

: obstruct, block

2

: dishonor, discredit

3

: to commit a foul against

4

: to hit (a baseball) foul

intransitive verb

1

: to commit a violation of the rules in a sport or game

2

: to hit a foul ball

3

: to become or be foul: such as

a

: decompose, rot

b

: to become encrusted, clogged, or choked with a foreign substance

c

: to become entangled or come into collision

foul

4 of 4

adverb

: in a foul manner : so as to be foul

Synonyms

Adjective

• bleak
• dirty
• inclement
• nasty
• raw
• rough
• squally
• stormy
• tempestuous
• turbulent

Verb

• befoul
• begrime
• bemire
• besmirch
• blacken
• daub
• dirty
• distain [archaic]
• gaum [dialect]
• grime
• mire
• muck
• muddy
• smirch
• smudge
• soil
• stain
• sully

Choose the Right Synonym for foul

dirty, filthy, foul, nasty, squalid mean conspicuously unclean or impure.

dirty emphasizes the presence of dirt more than an emotional reaction to it.

a dirty littered street

filthy carries a strong suggestion of offensiveness and typically of gradually accumulated dirt that begrimes and besmears.

a stained greasy floor, utterly filthy

foul implies extreme offensiveness and an accumulation of what is rotten or stinking.

a foul-smelling open sewer

nasty applies to what is actually foul or is repugnant to one expecting freshness, cleanliness, or sweetness.

it's a nasty job to clean up after a sick cat

In practice, nasty is often weakened to the point of being no more than a synonym of unpleasant or disagreeable.

had a nasty fall

his answer gave her a nasty shock

squalid adds to the idea of dirtiness and filth that of slovenly neglect.

squalid slums

All these terms are also applicable to moral uncleanness or baseness or obscenity.

dirty then stresses meanness or despicableness

don't ask me to do your dirty work

, while filthy and foul describe disgusting obscenity or loathsome behavior

filthy street language

a foul story of lust and greed

, and nasty implies a peculiarly offensive unpleasantness.

a stand-up comedian known for nasty humor

Distinctively, squalid implies sordidness as well as baseness and dirtiness.

engaged in a series of squalid affairs

Examples of foul in a Sentence

Adjective

the foul odor of rotten eggs

The medicine left a foul taste in my mouth.

The weather has been foul all week.

Noun

He hit several fouls in a row.

Verb

pollutants that foul the air

She fouled on her first long jump attempt.

He was fouled as he attempted the shot.

He kept fouling pitches into the stands.

Recent Examples on the Web

Adjective

Astros rookie Jacob Melton with a WILD catch in foul territory 😱 (via @astros)pic.twitter.com/KqrqRlDECr — B/R Walk-Off (@BRWalkoff) June 7, 2025 Otherwise, Melton was off to somewhat slow start to his career prior to the ankle injury. —Jon Vankin, MSNBC Newsweek, 18 June 2025

For Lynn, playing in the minors meant bad lighting and a short foul pole in right at the late McCoy Stadium that cost him home runs. —Bill Speros, Boston Herald, 15 June 2025

Noun

Isabelle Harrison replaced Jones, who didn’t shoot the pair of free throws following the foul. —Fiifi Frimpong, New York Daily News, 20 June 2025

Fever guard Sophie Cunningham also got into the fray with a hard foul on Sheldon late in the game. —Ryan Gaydos, FOXNews.com, 19 June 2025

Verb

After Messi made a nice run down the middle of the pitch, Porto midfielder Rodrigo Mora fouled the World Cup champion about a yard outside the penalty arc. —Michael Lewis, Forbes.com, 20 June 2025

Ozuna swung and fouled it off, but seeing how bad the swing was, Alvarez called for the same pitch again. —Abbey Mastracco, New York Daily News, 18 June 2025

Adverb

State gambling regulators have called foul, but the federal government has so far made no move to stop the companies. —Hana Kiros, The Atlantic, 5 June 2025

Five of those have been against the Cubs, who don’t chase a lot of pitches outside the zone (fourth fewest in MLB) and foul off a lot of two-strike pitches (third most in MLB). —Kevin Acee, San Diego Union-Tribune, 16 Apr. 2025

Word History

Etymology

Adjective and Noun

Middle English, from Old English fūl; akin to Old High German fūl rotten, Latin pus pus, putēre to stink, Greek pyon pus

First Known Use

Adjective

before the 12th century, in the meaning defined at sense 1a

Noun

before the 12th century, in the meaning defined at sense 4

Verb

before the 12th century, in the meaning defined at intransitive sense 1

Adverb

13th century, in the meaning defined above

Phrases Containing foul

• cry foul
• fall foul of
• foul ball
• foul line
• foul mouth
• foul of
• foul out
• foul play
• foul shot
• foul tip
• foul trouble
• foul up
• personal foul
• professional foul
• team foul
• technical foul

Rhymes for foul

• foule
• fowl
• growl
• howl
• jowl
• owl
• prowl
• scowl
• afoul
• wildfowl
• waterfowl

Kids Definition

foul

1 of 4 adjective

ˈfau̇(ə)l 

1

a

: disgusting in looks, taste, or smell

foul odor

b

: full of or covered with dirt

foul clothes

2

a

: detestable

a foul crime

b

: notably unpleasant or bad

a foul mood

c

: being vulgar or insulting

foul language

3

: being wet and stormy

foul weather

4

a

: very unfair

fair means or foul

b

: breaking a rule in a game or sport

a foul blow in boxing

5

: being outside the foul lines in baseball

a foul grounder

foully

ˈfau̇(l)-lē 

adverb

foulness

ˈfau̇(ə)l-nəs

noun

foul

2 of 4 noun

1

: an entanglement or collision in fishing or sailing

2

a

: a breaking of the rules in a game or sport

b

: free throw

3

: foul ball

foul

3 of 4 verb

1

: to make or become foul or filthy

foul the air

foul a stream

2

a

: to make a foul in a game or sport

b

: to hit a foul ball

3

: to become or cause to become entangled

foul the lines

foul

4 of 4 adverb

: in a foul manner : so as to be foul