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 animals have lungs similar to humans A virulent avian flu strain has made its way to a Utah mink farm, which could potentially open the door for the virus to spread to — and between — humans. — Devika Rao, TheWeek, 11 Nov. 2026

What over-the-counter medicines to keep on hand The standard flu kit covers fever, aches, congestion and cough. — Samantha Agate, Fort Worth Star-Telegram, 11 Nov. 2026

Bo Phillips developed flu-like symptoms and within days lapsed into a coma. — Noelle Crombie, ProPublica, 11 Nov. 2026

The number of people infected by an outbreak of avian flu in Washington State is much higher than initially reported, a farm workers' union has revealed. — Tom Sanders, MSNBC Newsweek, 11 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