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

On Tuesday, Secretary of Defense Pete Hegseth announced that the men and women who defend our nation will be able to choose whether to be protected from the flu. —Paul Friedrichs, STAT, 23 Apr. 2026

George says air pollution can make fighting infections like colds and the flu more difficult, along with other respiratory conditions. —Stephanie Stahl, CBS News, 23 Apr. 2026

Other available items include COVID-19 and flu test kits, period products, hygiene kits, wound care kits, sunscreen and socks. —Nathan Pilling, Kansas City Star, 22 Apr. 2026

According to an online flu dashboard last updated Wednesday, 83 flu deaths have been reported in Arkansas during the 2025-26 flu season. —Nathan Ansell, Arkansas Online, 22 Apr. 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