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 woman who died was in her 50s with underlying chronic medical conditions who was not vaccinated against the flu, according to a news release from the Sacramento County Public Health. — Rosalio Ahumada, Sacbee.com, 5 Nov. 2026

In general, everyone 6 months and older is urged to get an annual flu shot. — Jacqueline Howard, CNN Money, 4 Nov. 2026

County health officials said while flu activity has been low, indicators show higher cases than this time last year. — Elyssa Kaufman, CBS News, 4 Nov. 2026

Open to the public, the activation featured an interactive basketball bench, photo opportunities and the chance to book a flu shot appointment. — Arushi Jacob, Footwear News, 3 Nov. 2026

Word History

Etymology

by shortening

First Known Use

1839, in the meaning defined at sense 1

Phrases Containing flu

• anti-flu
• Asian flu
• avian flu
• bird flu
• blue flu
• flu season
• stomach flu
• 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