1a thick cloud of tiny water droplets suspended in the atmosphere at or near the earth’s surface that obscures or restricts visibility (to a greater extent than mist; strictly, reducing visibility to below 1 km):the collision occurred in thick fog
[in singular] an opaque mass of something in the atmosphere:a whirling fog of dust
Photography cloudiness that obscures the image on a developed negative or print.
2 [in singular] something that obscures and confuses a situation or someone’s thought processes:the origins of local government are lost in a fog of detail
verb (fogs, fogging, fogged)
1(with reference to a glass surface) cover or become covered with steam: [with object]:hot steam drifted about her, fogging up the window [no object]:the windshield was starting to fog up
Photography make (a film, negative, or print) obscure or cloudy.
2bewilder or puzzle (someone):she stared at him, confusion fogging her brain
make (an idea or situation) difficult to understand:the government has been fogging the issue
3treat with something, especially an insecticide, in the form of a spray:Winnipeg stopped fogging for mosquitoes three years ago
in a fog
in a state of perplexity; unable to think clearly or understand something.
the fog of war
confusion caused by the chaos of war or battle:he argues that the fog of war clouded everyone’s judgment
mid 16th century: perhaps a back-formation from foggy