brain fog

noun

: a usually temporary state of diminished mental capacity marked by inability to concentrate or to think or reason clearly

Examples of brain fog in a Sentence

Recent Examples on the Web
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.
Imagine living within the confines of four walls mostly in silence because of brain fog and sound sensitivity. Chicago Tribune, 25 Feb. 2025 But while studying computer science, Mangione, who had Lyme disease, developed brain fog, a debilitating symptom that attacked his thinking and decision-making. Liam Quinn, People.com, 18 Feb. 2025 Her initial fever and cough contorted into crushing fatigue, brain fog, blurred vision, dizziness, chest pain and more — and the debilitating symptoms never left. Farah Aziz Annesha, The Mercury News, 16 Feb. 2025 The market is surging in large part because of a generational shift that's seen Gen X and millennial women become far more vocal about the weight gain, hot flashes, brain fog and other telltale symptoms, posting online about their ordeals and pushing providers for better answers. Tina Reed, Axios, 23 Jan. 2025 See All Example Sentences for brain fog

Word History

First Known Use

1853, in the meaning defined above

Time Traveler
The first known use of brain fog was in 1853

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Cite this Entry

“Brain fog.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/brain%20fog. Accessed 5 Mar. 2025.

Medical Definition

brain fog

noun
: a usually temporary state of diminished mental capacity marked by inability to concentrate or to think or reason clearly
This brain fog can be a result of being overly stressed, tired, carrying extra weight, consuming too many calories or consistently consuming a diet poor in nutrients.Kylie Helgens, The Gazette (Cedar Rapids, Iowa)
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