English Reference

Word

foul

US/ˈfaʊɫ/

UK/fˈaʊl/

Definitions

01dirty or smelly

B1 · Intermediate

adj. having a very bad smell or being very dirty.

adj. containing or covered with offensive or unclean matter; physically loathsome or putrid.

“A foul smell was coming from the old bin in the kitchen.”

“The hikers were forced to turn back when they encountered the foul, stagnant water of the marshland.”

Antonyms

02bad weather

B2 · Upper Intermediate

adj. stormy, rainy, or generally unpleasant weather.

adj. pertaining to weather conditions that are stormy, turbulent, or otherwise unfavourable for travel.

“The ship stayed in the harbour because of the foul weather at sea.”

“Despite the foul weather forecast, the rescue team proceeded toward the summit to locate the stranded climbers.”

Antonyms

03rude language

B2 · Upper Intermediate

adj. using rude, offensive, or socially unacceptable words.

adj. characterised by obscene, vulgar, or abusive language.

“He was sent out of the classroom for using foul language.”

“The broadcast was interrupted after the interviewee began using foul language during the live segment.”

Antonyms

04unfair

B2 · Upper Intermediate

adj. not following the rules or being dishonest.

adj. violating the established rules of a game or the standards of fair play.

“The politician was accused of using foul means to win the election.”

“The referee ruled that the defender had used foul tactics to prevent the striker from reaching the ball.”

Antonyms

05to make dirty

B2 · Upper Intermediate

v. to make something dirty, especially with waste.

v. to contaminate or defile something with unclean matter.

“Dogs are not allowed on the beach so they don't foul the sand.”

“Industrial runoff continued to foul the river, making the water toxic for the local fish population.”

Antonyms

06to block or tangle

C1 · Advanced Science Technical

v. to block a pipe or get a rope tangled up.

v. to obstruct or clog a passage; in a nautical context, to become entangled or caught.

“The anchor line became fouled on some rocks under the water.”

“The mechanic explained that carbon deposits had fouled the spark plugs, causing the engine to misfire during acceleration.”

Synonyms

clogobstructentangle

Antonyms

clearuntangle

07to break sports rules

B1 · Intermediate Sports

v. to commit an unfair act against another player in a game.

v. to commit an infraction against an opponent or the rules of play in a sporting contest.

“The defender fouled the striker just outside the penalty area.”

“He was careful not to foul the shooter, knowing that any contact would result in two free throws for the opposing team.”

08a rule break

B1 · Intermediate Countable noun Sports

n. an action in a game that is against the rules.

n. an instance of breaking the rules in a sport, often involving illegal physical contact.

“The referee blew his whistle and called a foul on the blue team.”

“After committing his fifth personal foul, the star player was forced to leave the game for the remaining minutes.”

Etymology

Inherited from Middle English foul, from Old English fūl (“foul, dirty, unclean, impure, vile, corrupt, rotten, stinking, guilty”), from Proto-West Germanic fūl, from Proto-Germanic fūlaz (“foul, rotten”), from Proto-Indo-European *puH- (“to rot”). Cognate with Dutch vuil (“foul, dirty, filthy, obscene, lewd”), German faul (“foul, rotten, putrid, lazy”), German Low German fuul (“foul, rotten, putrid”), Faroese fúlur (“foul”), Icelandic fúll (“foul, rotten, sullen”), Danish ful (“nasty, ugly”), Norwegian Bokmål ful (“clever, sly”), and Swedish ful (“ugly, dirty, bad”), and through Indo-European, with Albanian fëlliq (“to make dirty”), Latin puter (“rotten”). More at putrid. Ancient Greek φαῦλος (phaûlos, “bad”) is a false cognate inasmuch as it is not from the same etymon, instead being cognate to few.

Inherited from Middle English foulen, fulen, from Old English fūlian (“to become foul; rot; decay”), from Proto-West Germanic fūlēn, from Proto-Germanic fūlāną (“to rot; decay”).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Word family

ADJECTIVE

foul(B1)

PHRASAL VERB

Idioms

Domains

NauticalSports

This entry

Exam level
CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B1 PreliminaryIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.4.0–5.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 3.0–3.544–71TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.550–784
Frequency
Common
Level
B1 · Intermediate
Updated

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English Reference