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

How to take care of a painful shingles rash Early on, shingles can feel a lot like the flu. —Alisa Hrustic, SELF, 9 Apr. 2025

Cuts to both the workforce and federal programs are hobbling measles outbreak response efforts and threatening the country’s ability to mitigate avian flu. —Jordan Miller, The Conversation, 3 Apr. 2025

The Trump administration has already purged a significant amount of data and information from important health websites, such as information on flu vaccination campaigns. —Omer Awan, Forbes.com, 3 Apr. 2025

Grant money helped the state respond to measles and avian flu and monitor wastewater to gauge levels of diseases like COVID-19, according to state officials. —Alex Derosier, Twin Cities, 2 Apr. 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