flu

noun

ˈflü How to pronounce flu (audio)
1
: influenza
2
: any of several virus diseases marked especially by respiratory or intestinal symptoms
flu-like
ˈflü-ˌlīk How to pronounce flu (audio)
adjective

Examples of flu in a Sentence

He came down with a bad bout of the flu.
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.
Such trust in God kept me untouched by an outbreak of the flu at my workplace several years ago. — André Kisonga, Christian Science Monitor, 30 June 2026 Bird flu news and reasons for cautious optimism The outlook isn’t all grim. — Ryan Brennan, Kansas City Star, 1 July 2026 Deaths from flu and pneumonia, meanwhile, rose to be the eighth-leading cause of death last year amid lower uptake of the flu shot. — Rachel Roubein, Washington Post, 2 July 2026 Kaydin's flu had progressed to strep pneumonia — and then necrotizing pneumonia. — Cara Lynn Shultz, PEOPLE, 1 July 2026 See All Example Sentences for flu

Word History

Etymology

by shortening

First Known Use

1839, in the meaning defined at sense 1

Time Traveler
The first known use of flu was in 1839

Phrases Containing flu

Rhymes for flu

See All Rhymes for flu

Browse Nearby Words

fltg
flu
fluate
See all Nearby Words

Cite this Entry

“Flu.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flu. Accessed 7 Jul. 2026.

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Kids Definition

flu

noun
ˈflü How to pronounce flu (audio)
1
: influenza sense 1
2
: any of several virus diseases that are something like a cold
flu-like
ˈflü-ˌlīk
adjective

Medical Definition

flu

noun
ˈflü How to pronounce flu (audio)
1
: influenza
2
: any of several chiefly viral illnesses marked especially by respiratory or gastrointestinal symptoms see intestinal flu
flu-like
-ˌlīk How to pronounce flu (audio)
adjective
also flulike
flu-like symptoms

More from Merriam-Webster on flu

Nglish: Translation of flu for Spanish Speakers

Britannica.com: Encyclopedia article about flu

Last Updated: - Updated example sentences
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