Synonyms

flash flood

American

noun

a sudden and destructive rush of water down a narrow gully or over a sloping surface, caused by heavy rainfall.

flash flood British

noun

a sudden short-lived torrent, usually caused by a heavy storm, esp in desert regions

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

flash flood Scientific

/ flăsh /

A sudden, localized flood of great volume and short duration, typically caused by unusually heavy rain in a semiarid area. Flash floods can reach their peak volume in a matter of a few minutes and often carry large loads of mud and rock fragments.

Related Words

See flood.

Etymology

Origin of flash flood

First recorded in 1935–40

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Authorities warn that the same storm system is now threatening other islands, with flash flood alerts and evacuation warnings issued for parts of Maui, Molokai and Lanai.

From Salon • Mar. 22, 2026

Honolulu Department of Emergency Management has issued multiple flash flood warnings and urged residents to move to higher ground and avoid flooded areas.

From BBC • Mar. 21, 2026

That’s because an expansive database specific to flash flood trends like this didn’t exist until now.

From The Wall Street Journal • Mar. 12, 2026

A fast moving storm drenched Los Angeles overnight and triggered a flash flood warning in a local burn scar Wednesday, according to the National Weather Service.

From Los Angeles Times • Feb. 11, 2026

She used to talk about her mommy and daddy watching over her after they died in the flash flood.

From "Missing May" by Cynthia Rylant

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023