\ ˈfȯg How to pronounce fog (audio) , fäg \

Definition of fog

 (Entry 1 of 2)

1a : vapor condensed to fine particles of water suspended in the lower atmosphere that differs from cloud only in being near the ground
b : a fine spray or a foam for firefighting
2 : a murky condition of the atmosphere or a substance causing it
3a : a state of confusion or bewilderment spent the morning in a fog
b : something that confuses or obscures hid behind a fog of rhetoric
4 : cloudiness or partial opacity in a developed photographic image caused by chemical action or stray radiation


fogged; fogging

Definition of fog (Entry 2 of 2)

transitive verb

1 : to cover, envelop, or suffuse with or as if with fog fog the barns with pesticide
2 : to make obscure or confusing accusations which fogged the real issues
3 : to make confused
4 : to produce fog on (something, such as a photographic film) during development

intransitive verb

1 : to become covered or thick with fog
2a : to become blurred by a covering of fog or mist
b : to become indistinct through exposure to light or radiation

Other Words from fog


fogless \ ˈfȯg-​ləs How to pronounce fog (audio) , ˈfäg-​ \ adjective

Synonyms & Antonyms for fog

Synonyms: Noun

Synonyms: Verb

Antonyms: Verb

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Examples of fog in a Sentence

Noun Heavy fog made it difficult to see the road. a climate marked by heavy fogs The fog reduced visibility to a quarter of a mile. This problem has me in a fog. Verb The steam from the pot was fogging the window near the stove. The bathroom was all fogged up after my shower. politicians who try to fog the issue instead of taking a stand
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Recent Examples on the Web: Noun America’s northernmost road is also its most dangerous, and Ms. Butcher reveals in a preliminary note that Joy Wiebe will die on the Dalton in August 2018, when her 53-foot tanker slips over a high shoulder in fog and overturns. Richard Adams Carey, WSJ, 6 Jan. 2022 Some fog and drizzle could persist into the morning. Washington Post, 29 Dec. 2021 The predawn liftoff from NASA’s Kennedy Space Center was barely visible in the fog and clouds, as the Falcon rocket hoisted a Dragon capsule loaded with more than 6,500 pounds of gear for the station's seven astronauts. Fox News, 22 Dec. 2021 Those valley inversions will strengthen through Wednesday, according to the National Weather Service, with increasing fog and haze, cold temperatures and declining air quality. Scott D. Pierce, The Salt Lake Tribune, 20 Dec. 2021 And the fog over variants of the coronavirus and their effects on consumers and businesses add to the difficulty of forecasting exactly what the impact might be of different policy choices open to the Fed. Don Lee Staff Writer, Los Angeles Times, 15 Dec. 2021 Friday started off with fog and colder temperatures with low clouds, but temperatures and humidity levels are expected to rise rapidly after sunset, the weather service said via Twitter. Shanzeh Ahmad,, 10 Dec. 2021 Valley inversions, where cooler air is trapped under a layer of warmer air, may keep dense fog and low clouds around much of the morning and into the afternoon. oregonlive, 29 Nov. 2021 The notion of a trip there shone out of the fog and dreariness of this whole era of history. Alexis C. Madrigal, The Atlantic, 9 Nov. 2021 Recent Examples on the Web: Verb My glasses do not fog up, and the cushion on the nose bridge is a welcomed bonus. Chloe Irving,, 23 Dec. 2021 The bookstore strains under quarantine and, while Flora lurks in its aisles, the whole world seems to fog up with ghosts: those killed by COVID-19; the invisible virus itself; previous victims of state violence. Katy Waldman, The New Yorker, 10 Nov. 2021 Aether Masks, co-founded by medical students at the U., placed third, winning $1,000 for its masks that won’t fog glasses. The Salt Lake Tribune, 4 Dec. 2021 Breezes may fully calm, making patchy fog a bit more possible, too. Washington Post, 31 Oct. 2021 Winter also brings an offshore flow that pushes fog up from the Central Valley, as well as a temperature inversion, with cold air near the ground and high air far above, forming a lid. Rachel Swan, San Francisco Chronicle, 15 Nov. 2021 People who wear glasses can also gauge if their masks are leaky by how much their lenses fog up, Cappa said. Compiled Democrat-gazette Staff From Wire Reports, Arkansas Online, 25 July 2021 Places where rivers and valleys are present are most susceptible to fog in the transition season, given relatively warm waters or the trapping nature of a valley bowl. Washington Post, 30 Sep. 2021 Taken together, these steps, plus the Texas and Arizona audits, reveal a broad effort by Trump and his acolytes to fog the truth about the 2020 election. Stephen Collinson, CNN, 24 Sep. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'fog.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of fog


1544, in the meaning defined at sense 1a


circa 1592, in the meaning defined at transitive sense 1

History and Etymology for fog


probably back-formation from foggy

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Last Updated

13 Jan 2022

Cite this Entry

“Fog.” Dictionary, Merriam-Webster, Accessed 24 Jan. 2022.

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More Definitions for fog



English Language Learners Definition of fog

 (Entry 1 of 2)

: many small drops of water floating in the air above the ground, the sea, etc.
: a state of mental confusion



English Language Learners Definition of fog (Entry 2 of 2)

: to cover or fill (something) with small drops of water : to make (something) foggy
: to become foggy
: to make (someone or something) confused


\ ˈfȯg How to pronounce fog (audio) , ˈfäg \

Kids Definition of fog

 (Entry 1 of 2)

1 : tiny drops of water floating in the air at or near the ground
2 : a confused state of mind I woke up in a fog.


fogged; fogging

Kids Definition of fog (Entry 2 of 2)

: to cover or become covered with tiny drops of water Steam from the shower fogged the mirror.


transitive verb
\ ˈfäg, ˈfȯg How to pronounce fog (audio) \
fogged; fogging

Medical Definition of fog

: to blur (a visual field) with lenses that prevent a sharp focus in order to relax accommodation before testing vision

More from Merriam-Webster on fog

Nglish: Translation of fog for Spanish Speakers

Britannica English: Translation of fog for Arabic Speakers Encyclopedia article about fog


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