Definition of foulnext
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foul

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verb

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Synonym Chooser

How does the adjective foul differ from other similar words?

Some common synonyms of foul are dirty, filthy, nasty, and squalid. While all these words mean "conspicuously unclean or impure," foul implies extreme offensiveness and an accumulation of what is rotten or stinking; it can also describe, for example, loathsome behavior.

a foul-smelling open sewer
a foul story of lust and greed

When can dirty be used instead of foul?

Although the words dirty and foul have much in common, dirty emphasizes the presence of dirt more than an emotional reaction to it or, figuratively, stresses meanness or despicableness.

a dirty littered street
don't ask me to do your dirty work

When could filthy be used to replace foul?

The meanings of filthy and foul largely overlap; however, filthy carries a strong suggestion of offensiveness and typically of gradually accumulated dirt that begrimes and besmears. Figuratively, it can also describe disgusting obscenity.

a stained greasy floor, utterly filthy
filthy street language

How is nasty related to other words for foul?

Nasty applies to what is actually foul or is repugnant to one expecting freshness, cleanliness, or sweetness; in practice, however, nasty is often weakened to the point of being no more than a synonym of unpleasant or disagreeable. When used figuratively, nasty implies a peculiarly offensive unpleasantness.

it's a nasty job to clean up after a sick cat
had a nasty fall
his answer gave her a nasty shock
a stand-up comedian known for nasty humor

When would squalid be a good substitute for foul?

In some situations, the words squalid and foul are roughly equivalent. However, squalid adds to the idea of dirtiness and filth that of slovenly neglect. Distinctively, its figurative use implies sordidness as well as baseness and dirtiness.

squalid slums
engaged in a series of squalid affairs

How does the adjective foul differ from other similar words?

Some common synonyms of foul are dirty, filthy, nasty, and squalid. While all these words mean "conspicuously unclean or impure," foul implies extreme offensiveness and an accumulation of what is rotten or stinking; it can also describe, for example, loathsome behavior.

a foul-smelling open sewer
a foul story of lust and greed

When can dirty be used instead of foul?

Although the words dirty and foul have much in common, dirty emphasizes the presence of dirt more than an emotional reaction to it or, figuratively, stresses meanness or despicableness.

a dirty littered street
don't ask me to do your dirty work

When could filthy be used to replace foul?

The meanings of filthy and foul largely overlap; however, filthy carries a strong suggestion of offensiveness and typically of gradually accumulated dirt that begrimes and besmears. Figuratively, it can also describe disgusting obscenity.

a stained greasy floor, utterly filthy
filthy street language

How is nasty related to other words for foul?

Nasty applies to what is actually foul or is repugnant to one expecting freshness, cleanliness, or sweetness; in practice, however, nasty is often weakened to the point of being no more than a synonym of unpleasant or disagreeable. When used figuratively, nasty implies a peculiarly offensive unpleasantness.

it's a nasty job to clean up after a sick cat
had a nasty fall
his answer gave her a nasty shock
a stand-up comedian known for nasty humor

When would squalid be a good substitute for foul?

In some situations, the words squalid and foul are roughly equivalent. However, squalid adds to the idea of dirtiness and filth that of slovenly neglect. Distinctively, its figurative use implies sordidness as well as baseness and dirtiness.

squalid slums
engaged in a series of squalid affairs

Example Sentences

Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Recent Examples of foul
Adjective
Key moment The Twins were unable to cash in on a pair of walks in the top of the eighth inning, stranding the bases loaded when Luke Keaschall popped up to the catcher in foul territory. Betsy Helfand, Twin Cities, 23 Apr. 2026 Jon, still her husband at the time, performed much of the physical work at another location south of Colorado Springs in Penrose, where neighbors in 2023 noticed a foul odor and complained. ABC News, 23 Apr. 2026
Verb
Orlando’s lead at halftime was 61-54, the last two of those points coming after Stewart fouled Carter with one-tenth of a second left. ABC News, 25 Apr. 2026 Wembanyama is in the NBA's concussion protocol after hitting his head on the court after he was fouled by Jrue Holiday on a drive to the basket in the second period of the 106-103 loss to Portland on Tuesday night at the Frost Bank Center. Tom Orsborn, San Antonio Express-News, 23 Apr. 2026 See All Example Sentences for foul
Recent Examples of Synonyms for foul
Adjective
  • The water is disgusting-looking.
    Adam England, PEOPLE, 24 Apr. 2026
  • These words then take on guilt by association because of the things we have been socialized to find unpleasant, uncomfortable, or disgusting.
    Literary Hub, Literary Hub, 21 Apr. 2026
Adjective
  • Smoothing turbulent waters and reminding both sides about their common bonds were what those trips were all about.
    ABC News, ABC News, 25 Apr. 2026
  • News of the lawsuit comes at a turbulent time for the Department of Human Services.
    Sam Tabachnik, Denver Post, 24 Apr. 2026
Adjective
  • Rich Batenburg, founder and CEO of The Clear Brands, says competitors in the marijuana industry who skirt the rules gain unfair advantages and present public health risks to patients and consumers.
    Karen Morfitt, CBS News, 30 Apr. 2026
  • For the early architects, food was always political and thus, so too was food justice—a direct affront to unfair systems.
    Literary Hub, Literary Hub, 29 Apr. 2026
Adjective
  • For instance, the ruling recognized that the government’s need to protect national security might require it to prevent publication of the number and location of troops and that the primary requirements of decency might require censorship of obscene publications.
    Encyclopedia Britannica, Encyclopedia Britannica, 29 Apr. 2026
  • Bounds said this gives the mayor the power to intervene when a member of the public engages in obscene speech or in speech intended to incite others in the room.
    Matthew Adams, Fort Worth Star-Telegram, 29 Apr. 2026
Adjective
  • Not the good, high-altitude ozone that shields us from dangerous UV light, but bad ozone, hovering right above ground level — stinking, brownish, grayish photochemical smog.
    Patt Morrison, Los Angeles Times, 26 Mar. 2026
  • Their solution to a stinking run was, comically, to rely on less than 23 per cent of possession and pick Madrid off with a classy volley from Martin Satriano, below.
    Phil Hay, New York Times, 3 Mar. 2026
Adjective
  • Reach-in coolers that didn’t keep food safe from bacteria growth and utensils stored in filthy spots shut down a Miami restaurant after inspection last week.
    David J. Neal, Miami Herald, 28 Apr. 2026
  • Stanley dealers were not in cutthroat competition for filthy lucre.
    Literary Hub, Literary Hub, 28 Apr. 2026
Verb
  • But as filming continued, Pidgeon appeared to dirty her butter blond with caramel and chocolate shades similar to Bessette-Kennedy’s, thanks to stylist Kari Hill.
    Kaleigh Werner, Footwear News, 25 Feb. 2026
  • With the help of your Instant Pot, spaghetti and meatballs come together in under an hour without dirtying multiple dishes.
    Jenna Sims, Southern Living, 24 Feb. 2026
Verb
  • Water sources are often polluted through run-off from lawns that contain herbicides.
    David Beaulieu, The Spruce, 28 Apr. 2026
  • As of last April, the state environmental agency was also lagging behind on inspections of polluting facilities, according to the audit.
    Christine Condon, Baltimore Sun, 24 Apr. 2026

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Cite this Entry

“Foul.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/foul. Accessed 2 May. 2026.

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