: any of several virus diseases marked especially by respiratory or intestinal symptoms
flu-like adjective

Example Sentences

He came down with a bad bout of the flu.
Recent Examples on the Web Last winter’s season was particularly strong, with children’s hospitals overwhelmed while the country also grappled with Covid-19 and the flu. Will Sullivan, Smithsonian Magazine, 9 May 2023 This is much the same way the agency tracks patterns in other respiratory diseases, such as the flu and RSV. Brenda Goodman, CNN, 5 May 2023 In some years, the burden of RSV disease comes close to the burden of flu in the elderly. Brady Knox, Washington Examiner, 3 May 2023 Twenty-four swans and one goose have died after an avian flu outbreak in Swansea, officials said. Kate Armanini, BostonGlobe.com, 21 Apr. 2023 Her father had died in the 1918 flu pandemic, leaving a void in her wedding party. Daniel Miller, Los Angeles Times, 13 Apr. 2023 An 11-year-old girl died of the flu in Cambodia in late February. Since January 2022, 11 cases of H5N1 have been reported in people. Dinah Voyles Pulver, USA TODAY, 12 Apr. 2023 The medications included prescription drugs and children’s cold and flu medicine as well as medications used to treat cancer, according to the report. Berkeley Lovelace Jr., NBC News, 11 Apr. 2023 Most patients hospitalized with flu had asthma, whereas those hospitalized for COVID-19 more frequently had diabetes and high blood pressure, and needed more assistance with daily activities. Melissa Healy, Anchorage Daily News, 7 Apr. 2023 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'flu.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


by shortening

First Known Use

1839, in the meaning defined at sense 1

Time Traveler
The first known use of flu was in 1839

Dictionary Entries Near flu

Cite this Entry

“Flu.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/flu. Accessed 31 May. 2023.

Kids Definition


: any of several virus diseases that are something like a cold

Medical Definition


: 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!