brain fog

noun

Problems in concentrating, thinking clearly, or remembering things; a sense of not being completely awake or mentally acute.

Meanings

nounbrain fog (uncountable)
  1. informaluncountableProblems in concentrating, thinking clearly, or remembering things; a sense of not being completely awake or mentally acute.

    While the warm, lingering days of summer are doubtless a wonderful thing, the brain fog that can accompany surging temperatures is actually real — and it doesn’t feel so wonderful.

    2018, Carolyn de Lorenzo, “The Scientific Reason You’re So Brain Foggy Over The Summer”, in Bustle
    3 more examples

    Then, as the brain fog lifted a little and cleared away, his chin quivered and he went on : “ Oh, Daisy, Daisy ; it comes back to me now, the years that are gone, and you as you were then. ”

    1886, Mary Jane Holmes, Bessie's Fortune, G. W. Carleton & Co., page 261

    That woman and her question must have emanated from the brain fog of some opposer to scientific temperance education who was trying to find out for himself whether three glasses of whisky or a bottle of Rhine wine is isodynamic with certain amounts of sugar, fat, and starch.

    1899, Mary H. Hunt, contribution to the discussion session on a lecture by W.O. Atwater, “Alcohol physiology and superintendence”. Proceedings of the Department of Superintendence, National Educational Association, page 82

    It’s becoming known as Covid brain fog: troubling cognitive symptoms that can include memory loss, confusion, difficulty focusing, dizziness and grasping for everyday words. Increasingly, Covid survivors say brain fog is impairing their ability to work and function normally.

    2020 October 11, Pam Belluck, “‘I Feel Like I Have Dementia’: Brain Fog Plagues Covid Survivors”, in New York Times

    Synonyms: cog fog, obnubilation

Synonyms & antonyms

nounProblems in concentrating, thinking clearly, or remembering things; a sense of not being completely awake or mentally acute.

Translations

Chinese Mandarin 腦霧 /脑雾
  • 腦霧 /脑雾 (nǎowù)mental condition
Finnish aivosumu
  • aivosumumental condition
French brouillard mental
  • brouillard mentalmental condition
German Nebel im Hirn, Hirnnebel
  • Nebel im Hirnmental condition
  • Hirnnebelmental condition
Japanese ブレインフォグ
  • ブレインフォグ (burēnfogu)mental condition
Spanish niebla cerebral
  • niebla cerebralmental condition
Cite this entry
APA

brain fog. (n.d.). In WatkinsX Dictionary. Retrieved November 3, 2026, from https://dictionary.watkinsx.com/word/brain%20fog

MLA

“brain fog.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/brain%20fog. Accessed November 3, 2026.

Chicago

WatkinsX Dictionary, s.v. “brain fog,” accessed November 3, 2026, https://dictionary.watkinsx.com/word/brain%20fog.

Source: brain fog on Wiktionary, CC BY-SA 4.0.