[ flash ]
See synonyms for flash on Thesaurus.com
  1. a brief, sudden burst of bright light: a flash of lightning.

  2. a sudden, brief outburst or display of joy, wit, etc.

  1. a very brief moment; instant: I'll be back in a flash.

  2. superficial, meretricious, or vulgar showiness; ostentatious display.

  3. Journalism. news flash.

  4. Photography.

  5. the sudden flame or intense heat produced by a bomb or other explosive device.

  6. a sudden thought, insight, inspiration, or vision.

  7. Metallurgy.

    • a ridge of metal left on a casting by a seam between parts of the mold.

    • a ridge formed at the edge of a forging or weld where excess metal has been squeezed out.

  8. Poker. a hand containing all five suits in a game played with a five-suit pack.

  9. a device, as a lock or sluice, for confining and releasing water to send a boat down a shallow stream.

  10. the rush of water thus produced.

  11. Obsolete. the cant or jargon of thieves, vagabonds, etc.

verb (used without object)
  1. to break forth into sudden flame or light, especially transiently or intermittently: a buoy flashing in the distance.

  2. to gleam.

  1. to burst suddenly into view or perception: The answer flashed into his mind.

  2. to move like a flash.

  3. to speak or behave with sudden anger, outrage, or the like (often followed by out): to flash out at a stupid remark.

  4. to break into sudden action.

  5. Slang. to open one's clothes and expose the genitals suddenly, and usually briefly, in public.

  6. Slang. to experience the intense effects of a narcotic or stimulant drug.

  7. to dash or splash, as the sea or waves.

  8. Archaic. to make a flash or sudden display.

verb (used with object)
  1. to emit or send forth (fire or light) in sudden flashes.

  2. to cause to flash, as powder by ignition or a sword by waving.

  1. to send forth like a flash.

  2. to communicate instantaneously, as by radio or telegraph.

  3. to make an ostentatious display of: He's forever flashing a large roll of bills.

  4. to display suddenly and briefly: She flashed her ID card at the guard.

  5. to change (water) instantly into steam by pouring or directing onto a hot surface.

  6. to increase the flow of water in (a river, channel, etc.).

  7. Glassmaking and Ceramics.

    • to coat (plain glass or a glass or ceramic object) with a layer of colored, opalescent, or white glass.

    • to apply (such a layer).

    • to color or make (glass) opaque by reheating.

  8. Building Trades. to protect from leakage with flashing.

  9. Cards. to expose (a card) in the process of dealing.

  10. Archaic. to dash or splash (water).

  1. happening suddenly and usually lasting a short time:a flash storm.

  2. very brief, fast, or short: flash freezing of vegetables;flash poetry and fiction.

  1. showy or ostentatious.

  2. caused by or used as protection against flash from an explosive device: flash injuries; flash clothing.

  3. counterfeit or sham.

  4. Computers. relating to or using flash memory: a flash drive.

  5. of or relating to followers of boxing, racing, etc.

  6. Obsolete. belonging to or connected with thieves, vagabonds, etc., or their cant or jargon.

Idioms about flash

  1. flash in the pan,

    • a brief, intense effort that produces no really significant result.

    • a person who makes such an effort; one who enjoys short-lived success.

  2. flash on, Slang.

    • to have a sudden thought, insight, or inspiration about.

    • to have a sudden, vivid memory or mental picture of: I just flashed on that day we spent at the lake.

    • to feel an instantaneous understanding and appreciation of.

Origin of flash

First recorded in 1350–1400; Middle English flasshen “to sprinkle, splash,” earlier flask(i)en; probably phonesthemic in origin; compare similar expressive words with fl- and -sh

synonym study For flash

18. Flash, glance, glint, glitter mean to send forth a sudden gleam (or gleams) of bright light. To flash is to send forth light with a sudden, transient brilliancy: A shooting star flashed briefly. To glance is to emit a brilliant flash of light as a reflection from a smooth surface: Sunlight glanced from the glass windshield. Glint suggests a hard bright gleam of reflected light, as from something polished or burnished: Light glints from silver or from burnished copper. To glitter is to reflect intermittent flashes of light from a hard surface: Ice glitters in the moonlight.

Other words for flash

Other words from flash

  • flash·ing·ly, adverb
  • outflash, verb (used with object)

Words Nearby flash

Other definitions for FLASH (2 of 2)

[ flash ]

  1. a precedence code for handling messages about initial enemy contact or operational combat messages of extreme urgency within the U.S. military.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use flash in a sentence

British Dictionary definitions for flash


/ (flæʃ) /

  1. a sudden short blaze of intense light or flame: a flash of sunlight

  2. a sudden occurrence or display, esp one suggestive of brilliance: a flash of understanding

  1. a very brief space of time: over in a flash

  2. an ostentatious display: a flash of her diamonds

  3. Also called: newsflash a short news announcement concerning a new event

  4. Also called: patch mainly British an insignia or emblem worn on a uniform, vehicle, etc, to identify its military formation

  5. a patch of bright colour on a dark background, such as light marking on an animal

  6. a volatile mixture of inorganic salts used to produce a glaze on bricks or tiles

    • a sudden rush of water down a river or watercourse

    • a device, such as a sluice, for producing such a rush

  7. photog informal short for flashlight (def. 2), flash photography

  8. a ridge of thin metal or plastic formed on a moulded object by the extrusion of excess material between dies

  9. Yorkshire and Lancashire dialect a pond, esp one produced as a consequence of subsidence

  10. (modifier) involving, using, or produced by a flash of heat, light, etc: flash blindness; flash distillation

  11. flash in the pan a project, person, etc, that enjoys only short-lived success, notoriety, etc

  1. informal ostentatious or vulgar

  2. informal of or relating to gamblers and followers of boxing and racing

  1. sham or counterfeit

  2. informal relating to or characteristic of the criminal underworld

  3. brief and rapid: flash freezing

  1. to burst or cause to burst suddenly or intermittently into flame

  2. to emit or reflect or cause to emit or reflect light suddenly or intermittently

  1. (intr) to move very fast: he flashed by on his bicycle

  2. (intr) to come rapidly (into the mind or vision)

  3. (intr; foll by out or up) to appear like a sudden light: his anger really flashes out at times

    • to signal or communicate very fast: to flash a message

    • to signal by use of a light, such as car headlights

  4. (tr) informal to display ostentatiously: to flash money around

  5. (tr) informal to show suddenly and briefly

  6. (intr) British slang to expose oneself indecently

  7. (tr) to cover (a roof) with flashing

  8. to send a sudden rush of water down (a river, etc), or to carry (a vessel) down by this method

  9. (in the making of glass) to coat (glass) with a thin layer of glass of a different colour

  10. (tr) to subject to a brief pulse of heat or radiation

  11. (tr) to change (a liquid) to a gas by causing it to hit a hot surface

  12. obsolete to splash or dash (water)

Origin of flash

C14 (in the sense: to rush, as of water): of unknown origin

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

Other Idioms and Phrases with flash


In addition to the idiom beginning with flash

  • flash in the pan

also see:

  • in a flash
  • quick as a wink (flash)

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.