noun, slang ·Common ·High school level

Definitions

Noun

1. 1
   Influenza. uncountable, usually

   "catch flu"

2. 2
   an acute febrile highly contagious viral disease wordnet
3. 3
   Stomach flu. informal, uncountable, usually

Synonyms

All synonyms

influenzagrippegrippeacute articular rheumatismacute bronchitisadenoiditis

Example

More examples

"Can we check the rapid spread of the 'flu?"

Etymology

Clipping of influenza.

Related phrases

24-hour fluAsian fluEgyptian fluEkka fluFlu ManchuHong Kong fluMexican fluNavajo fluRussian fluSpanish fluTeflon fluWu flu

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.