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• flash
  flash

  noun

  a brief, sudden burst of bright light.
• FLASH
  FLASH

  noun

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

flash

¹ American  

[flash] / flæʃ /

noun

• flashes
  plural

1. a brief, sudden burst of bright light.

   The sky lit up with a flash of lightning.

   Synonyms:

   glare, gleam, flare

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

   Her brilliant eye for detail and quiet flashes of humor make the book a joy to read.

3. a very brief moment; instant.

   I'll be back in a flash.

   Synonyms:

   wink, twinkling

4. Informal. flashlight.

5. Journalism. news flash.

6. Photography.

   1. bright artificial light thrown briefly upon a subject during an exposure.

   2. flash lamp.

   3. flashbulb.

   4. electronic flash.

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

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

   I smelled the sea breeze and had a flash of my childhood summers at the beach.

9. a showy or ostentatious display.

10. Slang. rush.

11. Metallurgy.

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

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

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

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

    2. the rush of water thus produced.

14. hot flash.

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

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verb (used without object)

• flashes,
  present (3rd person singular)
• flashed,
  past participle,  past
• flashing
  present participle

1. to break forth into sudden flame or light, especially transiently or intermittently.

   We saw a buoy flashing in the distance.

2. to gleam.

   The car's chrome bumpers flashed in the sun.

   Synonyms:

   scintillate

3. to burst suddenly into view or perception.

   The answer flashed into his mind.

4. to move very suddenly and quickly.

5. to speak or behave with sudden anger, outrage, or the like (often followed byout ).

   to flash out at a stupid remark.

6. to break into sudden action.

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

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

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

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

verb (used with object)

• flashes,
  present (3rd person singular)
• flashed,
  past participle,  past
• flashing
  present participle

1. to emit or send forth (fire or light) in sudden bursts.

2. to cause to emit or reflect light.

   There was a driver tailgating them who kept flashing his high beams and honking his horn.

   A beekeeper I knew used to flash a mirror at his hive to help settle them.

3. to communicate instantly.

   The airline flashed the updated flight time on the overhead display.

4. to make an ostentatious display of.

   He's forever flashing a large roll of bills.

5. to display suddenly and briefly.

   She flashed her ID card at the guard.

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

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

8. Glassmaking and Ceramics.

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

   2. to apply (such a layer).

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

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

10. Computers.

    1. to write a program, file, etc. to the part of (a device's) memory that is reprogrammable and retains information even with the power turned off.

       If you're still having problems, you can flash the router.

    2. to write (a program, file, etc.) to the part of a device's memory that is reprogrammable and retains information even with the power turned off.

       I flashed the device's firmware using the latest version available.

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

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

adjective

1. happening suddenly and usually lasting a short time.

   a flash storm.

2. very brief, fast, or short: flash poetry and fiction.

   flash freezing of vegetables;

   flash poetry and fiction.

3. Computers. relating to or using a type of reprogrammable memory that retains information even with the power turned off.

   a flash drive.

4. showy or ostentatious.

   Synonyms:

   ostentatious, pretentious, tawdry, gaudy, flashy

5. caused by or used as protection against flash from an explosive device.

   flash injuries; flash clothing.

6. counterfeit or sham.

   Synonyms:

   fake, false

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

idioms

1. flash on,

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

   2. to have a sudden, vivid memory or mental picture of.

      I just flashed on that day we spent at the lake.

   3. to feel an instantaneous understanding and appreciation of.

2. flash in the pan,

   1. a brief, intense effort that produces no significant result.

   2. a person or thing that enjoys short-lived success.

FLASH ² American  

[flash] / flæʃ /

noun

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

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flash British  

/ flæʃ /

noun

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

3. a very brief space of time

   over in a flash

4. an ostentatious display

   a flash of her diamonds

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

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

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

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

9. 1. a sudden rush of water down a river or watercourse

   2. a device, such as a sluice, for producing such a rush

10. informal photog short for flashlight flash photography

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

12. dialect a pond, esp one produced as a consequence of subsidence

13. (modifier) involving, using, or produced by a flash of heat, light, etc

    flash blindness

    flash distillation

14. a project, person, etc, that enjoys only short-lived success, notoriety, etc

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adjective

1. informal ostentatious or vulgar

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

3. sham or counterfeit

4. informal relating to or characteristic of the criminal underworld

5. brief and rapid

   flash freezing

verb

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

3. (intr) to move very fast

   he flashed by on his bicycle

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

5. (intr; foll by out or up) to appear like a sudden light

   his anger really flashes out at times

6. 1. to signal or communicate very fast

      to flash a message

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

7. informal (tr) to display ostentatiously

   to flash money around

8. informal (tr) to show suddenly and briefly

9. slang (intr) to expose oneself indecently

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

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

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

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

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

15. obsolete to splash or dash (water)

flash More Idioms  

More idioms and phrases containing flash

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

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Synonym Usage

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 Word Forms

Derived Forms

• outflash
  verb (used with object)
• flashingly
  adverb

Inflected Forms

Nouns

• flashes
  plural

Participles

• flashing
  present
• flashed
  past

Conjugated Forms

Present

• flash
  simple
• flashes
  simple
• have flashed
  perfect
• has flashed
  perfect
• am flashing
  progressive
• are flashing
  progressive
• is flashing
  progressive
• have been flashing
  perfect progressive
• has been flashing
  perfect progressive

Past

• flashed
  simple
• had flashed
  perfect
• was flashing
  progressive
• were flashing
  progressive
• had been flashing
  perfect progressive

Future

• will flash
  simple
• will have flashed
  perfect
• will be flashing
  progressive
• will have been flashing
  perfect progressive

Etymology

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

Explanation

Ever notice how quick the flash is on a camera? That's how fast other types of flashes are, including the super-fast superhero The Flash. Whether you're talking about a flash of lighting or a flash of insight, a flash is quick and bright and sudden. There aren't any slow, long flashes. Because flashes are so fast, the word is often used for anything that happens really quickly: a flash is as fast as a New York minute, the blink of an eye, a heartbeat, an instant, a jiffy, or a split second.

Example Sentences

See Examples For:

flash FLASH flashes flashed flashing

In Japan, Kioxia and Sandisk are investing more than $31 billion to drive the large-scale supply of flash memory chips.

From The Wall Street Journal ● Sep. 14, 2026

As a result of climate change, the frequency and intensity of flash flooding is expected to increase significantly in the coming years here.

From Science Daily ● Sep. 10, 2026

The center warned that the combination of a storm surge and tide could flood normally dry areas near the coast in Kauai and Niihau, and a flash flood warning was issued for Kauai on Monday.

From Barron's ● Sep. 7, 2026

Why we’re to care about this apparent flash of horror, if not of conscience, remains unexplained.

From Los Angeles Times ● Sep. 5, 2026

Traveler—how could he be anyone but Traveler?—shifted the books in his arms, and as people shuffled forward, I caught the faintest flash of his profile.

From "Bye Forever, I Guess" by Jodi Meadows

That’s difficult for some teachers, said Kari Kesler, one of the lead authors of FLASH.

From Seattle Times ● Dec. 24, 2017

It’s called FLASH, for Family Life and Sexual Health, and every year, teachers nationwide download tens of thousands of its lesson plans.

From Seattle Times ● Dec. 24, 2017

Magoč, T. & Salzberg, S. L. FLASH: fast length adjustment of short reads to improve genome assemblies.

From Nature ● Nov. 14, 2017

Two categories stood out as particularly deserving of further investigation: reproductive symptoms, including changes in menstrual cycles, and problems involving body temperature, such as chills and hot flashes.

From Science Daily ● Sep. 13, 2026

A maiden season in F1 last year followed in which Antonelli showed flashes of promise but little that indicated what has happened this year would follow.

From BBC ● Sep. 6, 2026

Last year, the Chargers used the identical 22nd pick on North Carolina running back Omarion Hampton, who showed flashes of promise as a rookie but also slogged through an injury-plagued season.

From Los Angeles Times ● Sep. 6, 2026

AFP journalists in the capital heard around a dozen loud explosions and saw flashes in sky early Tuesday moments after the air force warned of incoming ballistic missiles.

From Barron's ● Sep. 1, 2026

As I watch, a small explosion flashes from the launch port and one shuttle dock rail skews to one side, while the other completely detaches.

From "The Last Cuentista" by Donna Barba Higuera

I flew American from Los Angeles to Chicago for an upcoming column and United from Chicago to Newark because they flashed a last-minute upgrade in the app.

From The Wall Street Journal ● Sep. 11, 2026

Hampton, the No. 22 overall pick in the 2025 draft, flashed his skills as a rookie.

From Los Angeles Times ● Aug. 24, 2026

On Tuesday, the S&P 500 flashed a vigorous breakout from a technical pattern known as a “flag” or a “wedge” — typically a bullish signal, according to Adam Turnquist, chief technical strategist at LPL Financial.

From MarketWatch ● Aug. 4, 2026

"The screen went blank, flashed several times and the phone appeared to restart," according to CBP officers.

From Barron's ● Jul. 29, 2026

Lightning flashed in the swirling mass for hours and hours.

From "Mountain of Fire" by Rebecca E. F. Barone

Valuations, earnings expectations, market concentration, equity issuance, and foreign buying are all flashing warning signs for the AI-fueled stock rally.

From Barron's ● Sep. 11, 2026

“There’s like a million different signs that the freeway ends,” he said Wednesday: flashing lights, signs, rumble strips.

From Los Angeles Times ● Sep. 2, 2026

Treasurys, long considered an ultrasafe asset by investors, was flashing a warning light.

From The Wall Street Journal ● Sep. 2, 2026

Throughout the monthslong crisis, though, the strategists said they’ve been flashing back to the 2003 Iraq war and then Defense Sec.

From MarketWatch ● Aug. 28, 2026

Small mammals were scurrying away from the two of them, and a few birds were up chasing after flashing fireflies.

From "Healer of the Water Monster" by Brian Young

Related Words

• beam
• blaze
• burst
• flame
• flare
• glare
• gleam
• glimmer
• glint
• glitter
• glow
• radiation
• ray
• reflection
• spark
• sparkle
• vision