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 farm’s owners disputed the CFIA’s conclusions, arguing that the ostriches that survived the flu might offer disease-fighting antibodies for research – an idea that Kennedy endorsed in his letter to the CFIA in May after meeting with Canadian officials. —Max Saltman, CNN Money, 7 Nov. 2025

As of now, only inmates experiencing flu-like symptoms are being tested, according to the department’s website. —Miami Herald, 7 Nov. 2025

The hospital had previously required Adaline to be vaccinated against COVID-19 and the flu in order to be put on the list, which her parents weren't willing to do. —Victoria Moorwood, Cincinnati Enquirer, 6 Nov. 2025

Karen Tait, a former office manager from Norfolk, England, started experiencing flu-like symptoms in October 2022. —Vanessa Etienne, PEOPLE, 5 Nov. 2025

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
• 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