flash

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

Informal. flashlight (def. 1).

superficial, meretricious, or vulgar showiness; ostentatious display.

Journalism. news flash.

Photography.

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

a sudden thought, insight, inspiration, or vision.

Slang. rush¹ (def. 24).

Metallurgy.

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

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

the rush of water thus produced.

hot flash.

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

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

to move like a flash.

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

to break into sudden action.

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

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

to dash or splash, as the sea or waves.

Archaic. to make a flash or sudden display.

to send forth like a flash.

to communicate instantaneously, as by radio or telegraph.

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

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

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

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

Glassmaking and Ceramics.

Building Trades. to protect from leakage with flashing.

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

Archaic. to dash or splash (water).

a very brief space of time: over in a flash

an ostentatious display: a flash of her diamonds

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

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

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

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

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

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

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

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

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

sham or counterfeit

informal relating to or characteristic of the criminal underworld

brief and rapid: flash freezing

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

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

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

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

(tr) informal to show suddenly and briefly

(intr) British slang to expose oneself indecently

(tr) to cover (a roof) with flashing

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

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

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

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

obsolete to splash or dash (water)