1
2
: any of several virus diseases marked especially by respiratory or intestinal symptoms
flu-like 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.
Related article Bird flu variant found in Nevada cows shows signs of adaptation to mammals OPPR also coordinated with the US Department of Veterans Affairs, the Federal Emergency Management Agency and partners from industry to maintain therapeutics in the Strategic National Stockpile. Brenda Goodman, CNN, 17 Mar. 2025 Higher egg prices demonstrates this very well, since avian flu and the culling of infected flocks are the prime driver, but that hasn’t stopped efforts to assign responsibility. Michael Lynch, Forbes, 14 Mar. 2025 That means the measles virus can destroy the immunity people have built up over time to things like the common cold, the flu, bacteria that can cause pneumonia or any other pathogen. Akshay Syal, M.d., NBC News, 12 Mar. 2025 Egg production has been hit hard by avian flu outbreaks. Faisal Kutty, Newsweek, 11 Mar. 2025 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

Browse Nearby Words

Cite this Entry

“Flu.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flu. Accessed 23 Mar. 2025.

Kids Definition

flu

noun
1
2
: any of several virus diseases that are something like a cold
flu-like
ˈflü-ˌlīk
adjective

Medical Definition

flu

noun
1
2
: any of several chiefly viral illnesses marked especially by respiratory or gastrointestinal symptoms see intestinal flu
flu-like adjective
also flulike
flu-like symptoms

More from Merriam-Webster on flu

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!