fog

1 of 2

noun

ˈfȯg 

fäg

1

a

: 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

3

a

: 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

fogless

ˈfȯg-ləs 

ˈfäg-

adjective

fog

2 of 2

verb

fogged; fogging

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

2

a

: to become blurred by a covering of fog or mist

b

: to become indistinct through exposure to light or radiation

Synonyms

Noun

• daze
• dazedness
• haze
• muddle
• spin
• swoon

Verb

• becloud
• befog
• blur
• cloud
• confuse
• muddy
• obfuscate

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

Recent Examples on the Web

Noun

In extremely dense fog where visibility is near zero, the best course of action is to first turn on your hazard lights, then simply pull into a safe location such as a parking lot of a local business, and stop. —Star-Telegram Weather Bot, Fort Worth Star-Telegram, 7 May 2025

Fans saw through the fog from the beginning, and each slight felt more telling than the last. —Charlotte Walsh, Vulture, 5 May 2025

Verb

There are lots of benefits to the Astral Sphere’s more anatomical shape—the extra room between your eye and the lens can reduce the risk of fogging, as well as increase clarity and comfort. —Lauren Wingenroth, SELF, 1 May 2025

Known for its calming, anti-anxiety effects, lavender gives the Victorian London fog a medicinal boost, while the blueberry green tea provides energy and antioxidants. —Anna Haines, Forbes, 12 Dec. 2024

Word History

Etymology

Noun

probably back-formation from foggy

First Known Use

Noun

1544, in the meaning defined at sense 1a

Verb

circa 1592, in the meaning defined at transitive sense 1

Phrases Containing fog

• brain fog
• fog lamp
• fog light
• ice fog

Rhymes for fog

• blog
• bog
• clog
• cog
• dog
• flog
• frog
• grog
• hog
• jog
• log
• og

Kids Definition

fog

1 of 2 noun

ˈfȯg 

ˈfäg

1

a

: fine particles of water floating in the atmosphere near the ground

b

: a fine spray or a foam for firefighting

2

: a gloomy condition of the atmosphere or a substance causing it

3

: a state of mental confusion

spent the morning in a fog

fog

2 of 2 verb

fogged; fogging

1

: to cover or become covered with or as if with fog

2

: to make confused

Medical Definition

fog

transitive verb

ˈfäg, ˈfȯg 

fogged; fogging

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