chronic fatigue syndrome

noun

: a disorder of unknown cause that is characterized by persistent profound fatigue usually accompanied by other symptoms (such as headache and tender lymph nodes) unrelated to any preexisting medical condition
—abbreviation CFS

Examples of chronic fatigue syndrome in a Sentence

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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.
Mental health conditions such as depression can sap both energy and motivation, while medical issues including hypothyroidism, anemia and chronic fatigue syndrome can also cause debilitating symptoms. — Daryl Austin, USA Today, 21 Aug. 2026 But to meet the needs of patients with diseases such as fibromyalgia, IBS, chronic fatigue syndrome, and long COVID, medicine will need to loosen its reliance on the magic-bullet model. — Jason Liebowitz, The Atlantic, 12 May 2026 At university, he was diagnosed with ME/CFS (Myalgic encephalomyelitis, also called chronic fatigue syndrome). — Alison Coleman, Forbes.com, 4 Mar. 2026 It's also been studied for chronic fatigue syndrome, but with mixed results. — Megan Nunn, Verywell Health, 28 Jan. 2026 See All Example Sentences for chronic fatigue syndrome

Word History

First Known Use

1947, in the meaning defined above

Time Traveler
The first known use of chronic fatigue syndrome was in 1947

Rhymes for chronic fatigue syndrome

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Browse Nearby Words

chronic disease
chronic fatigue syndrome
chronicity
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Cite this Entry

“Chronic fatigue syndrome.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/chronic%20fatigue%20syndrome. Accessed 28 Aug. 2026.

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Medical Definition

chronic fatigue syndrome

noun
: a disorder of uncertain cause that is characterized by persistent profound fatigue usually accompanied by impairment in short-term memory or concentration, sore throat, tender lymph nodes, muscle or joint pain, and headache unrelated to any preexisting medical condition and that typically has an onset at about 30 years of age
—abbreviation CFS

called also myalgic encephalomyelitis

More from Merriam-Webster on chronic fatigue syndrome

Britannica.com: Encyclopedia article about chronic fatigue syndrome

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