flu

noun

ˈflü 

1

: influenza

2

: any of several virus diseases marked especially by respiratory or intestinal symptoms

flu-like

ˈflü-ˌlīk 

adjective

Examples of flu in a Sentence

He came down with a bad bout of the flu.

Recent Examples on the Web

The lunch had been scheduled for weeks, the official said, and it had been rescheduled because Bannon got the flu. —Nbc News, NBC news, 20 June 2025

The machine and statistical models used during this study were able to use levels of airborne fungal spores to predict surges in COVID-19 and the flu with high accuracy. —Stephanie Edwards, Discover Magazine, 20 June 2025

Hammond has written and edited explainers on a number of health and wellness topics, including racial disparities in HIV treatment, the metabolic benefits of cold exposure, how the flu shot works, and solutions for seasonal dermatology woes. —Tom Gavin, EverydayHealth.com, 18 June 2025

But the agenda also includes a vote for these types of vaccines, offering a stronger signal that the CDC may alter its recommendations for flu vaccines. —ArsTechnica, 18 June 2025

Word History

Etymology

by shortening

First Known Use

1839, in the meaning defined at sense 1

Phrases Containing flu

• anti-flu
• Asian flu
• bird flu
• blue flu
• flu season
• swine flu
• yuppie flu

Rhymes for flu

• blew
• blue
• boo
• brew
• chew
• chou
• clue
• coo
• coup
• crew
• cue
• dew

Kids Definition

flu

noun

ˈflü 

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 

1

: influenza

2

: any of several chiefly viral illnesses marked especially by respiratory or gastrointestinal symptoms see intestinal flu

flu-like

-ˌlīk 

adjective

also flulike

flu-like symptoms