adjective, foul·er, foul·est.
  1. grossly offensive to the senses; disgustingly loathsome; noisome: a foul smell.
  2. containing or characterized by offensive or noisome matter: foul air; foul stagnant water.
  3. filthy or dirty, as places, receptacles, clothes, etc.
  4. muddy, as a road.
  5. clogged or obstructed with foreign matter: a foul gas jet.
  6. unfavorable or stormy: foul weather.
  7. contrary, violent, or unfavorable, as the wind.
  8. grossly offensive in a moral sense.
  9. abominable, wicked, or vile, as deeds, crime, slander, etc.
  10. scurrilous, profane, or obscene; offensive: foul language.
  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.
  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.
  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)
  1. to make foul; defile; soil.
  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.
  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 or away): He fouled off two curves before being struck out on a fastball.
verb (used without object)
  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 Phrases
  1. foul out,
    1. be put out by hitting a foul ball caught on the fly by a player on the opposing team.
    2. be expelled from a game for having committed more fouls than is allowed.
  2. foul up, Informal. to cause confusion or disorder; bungle; spoil.
  1. fall foul/afoul of,
    1. to collide with, as ships.
    2. to come into conflict with; quarrel.
    3. to make an attack; assault.
  2. foul one's nest, to dishonor one's own home, family, or the like.
  3. run foul/afoul of, to come into collision or controversy with: to run foul of the press.

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.
Related formsfoul·ly, adverbo·ver·foul, adjectiveo·ver·foul·ly, adverbo·ver·foul·ness, nounun·foul, adjectiveun·foul·ly, adverbun·fouled, adjective
Can be confusedfoul fowl

Synonyms for foul

1. repulsive, repellent. 2. fetid, putrid, stinking. 3. unclean, polluted, sullied, soiled, stained, tainted, impure. 6. rainy, tempestuous. 7. adverse. 9. base, shameful, infamous. 10. smutty, vulgar, coarse, low. 24. sully, stain, dirty, besmirch, taint, pollute. 28. shame.

Synonym study

3. See dirty.

Antonyms for foul

1. pleasant. 3, 24. clean. 5, 6. clear. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for foulest

Contemporary Examples of foulest

Historical Examples of foulest

  • "He'll be hanged with the foulest collier yet," growled one of the men.

  • He poured forth a stream of the foulest abuse which the policeman had ever heard.

  • In their private practices they perform the darkest and foulest crimes.

  • "Fairest without is often foulest within, Bigot," answered Cadet, doggedly.

    The Golden Dog

    William Kirby

  • She had done him the foulest of wrongs,—she had ravaged his life.

British Dictionary definitions for foulest


  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; vulgarfoul language
  7. not in accordance with accepted standards or established rules; unfairto resort to foul means
  8. (esp of weather) unpleasant or adverse
  9. blocked or obstructed with dirt or foreign mattera foul drain
  10. entangled or impededa foul anchor
  11. (of the bottom of a vessel) covered with barnacles and other growth that slow forward motion
  12. informal unsatisfactory or uninteresting; bada foul book
  13. archaic ugly
  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
  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 ondo not let your dog foul the footpath
  10. to collide with (a boat, etc)
  1. in a foul or unfair manner
  2. fall foul of
    1. to come into conflict with
    2. nauticalto come into collision with
See also foul up
Derived Formsfoully, adverb

Word Origin for foul

Old English fūl; related to Old Norse fūll, Gothic fūls smelling offensively, Latin pūs pus, Greek puol pus
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for foulest



Old English ful "rotten, unclean, vile, corrupt, offensive to the senses," from Proto-Germanic *fulaz (cf. Old Saxon and Old Frisian ful, Middle Dutch voul, Dutch vuil, Old High German fül, German faul, Gothic füls), from root *fu-, corresponding to PIE *pu-, perhaps from the sound made in reaction to smelling something bad (cf. Sanskrit puyati "rots, stinks," putih "foul, rotten;" Greek puon "discharge from a sore;" Latin pus "putrid matter," putere "to stink," putridus "rotten;" Lithuanian puviu "to rot").

Old English ful occasionally meant "ugly" (as contrasted with fæger (adj.), modern fair (adj.)), a sense frequently found in Middle English, and the cognate in Swedish is the usual word for "ugly." Of weather, first recorded late 14c. In the sporting sense of "irregular, unfair" it is first attested 1797, though foul play is recorded from mid-15c. Baseball sense of "out of play" attested by 1860. Foulmart was a Middle English word for "polecat" (from Old English mearð "marten").



Old English fulian "to become foul, rot," from ful (see foul (adj.)). Related: Fouled; fouling.

Online Etymology Dictionary, © 2010 Douglas Harper

Idioms and Phrases with foulest


In addition to the idioms beginning with foul

  • foul one's nest
  • foul play
  • foul up

also see:

  • run afoul of
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.