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

These indicators can include cold and flu-like symptoms, a red rash or white spots inside the mouth. —Katie Silver, NPR, 28 Mar. 2026

Currently, scientists must predict which strains of flu virus will be prevalent in the coming season months in advance. —Meghan Bartels, Scientific American, 27 Mar. 2026

Summer meetings typically involve official recommendations for fall shots, such as those for flu and Covid. —Erika Edwards, NBC news, 27 Mar. 2026

Every year, scientists try to predict months in advance which strains will be circulating in the coming flu and COVID-19 season. —Dallas Morning News, 27 Mar. 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