2. To break forth, as a sudden flood of light; to burst instantly and brightly on the sight; to show a momentary brilliancy; to come or pass like a flash. [ 1913 Webster ]

Names which have flashed and thundered as the watch words of unnumbered struggles. Talfourd. [ 1913 Webster ]

The object is made to flash upon the eye of the mind. M. Arnold. [ 1913 Webster ]

A thought flashed through me, which I clothed in act. Tennyson. [ 1913 Webster ]

3. To burst forth like a sudden flame; to break out violently; to rush hastily. [ 1913 Webster ]

Every hour
He flashes into one gross crime or other. Shak. [ 1913 Webster ]

flash in the pan, a failure or a poor performance, especially after a normal or auspicious start; also, a person whose initial performance appears augur success but who fails to achieve anything notable. From 4th pan, n., sense 3 -- part of a flintlock. Occasionally, the powder in the pan of a flintlock would flash without conveying the fire to the charge, and the ball would fail to be discharged. Thus, a good or even spectacular beginning that eventually achieves little came to be called a flash in the pan. --
To flash in the pan, to fail of success, especially after a normal or auspicious start. [ Colloq. ] See under Flash, a burst of light. Bartlett. [ 1913 Webster +PJC ]

Syn. -- Flash, Glitter, Gleam, Glisten, Glister. Flash differs from glitter and gleam, denoting a flood or wide extent of light. The latter words may express the issuing of light from a small object, or from a pencil of rays. Flash differs from other words, also, in denoting suddenness of appearance and disappearance. Flashing differs from exploding or disploding in not being accompanied with a loud report. To glisten, or glister, is to shine with a soft and fitful luster, as eyes suffused with tears, or flowers wet with dew. [ 1913 Webster ]

The chariot of paternal Deity,
Flashing thick flames. Milton. [ 1913 Webster ]

2. To convey as by a flash; to light up, as by a sudden flame or light; as, to flash a message along the wires; to flash conviction on the mind. [ 1913 Webster ]

3. (Glass Making) To cover with a thin layer, as objects of glass with glass of a different color. See Flashing, n., 3 (b). [ 1913 Webster ]

4. To trick up in a showy manner. [ 1913 Webster ]

Limning and flashing it with various dyes. A. Brewer. [ 1913 Webster ]

5. [ Perh. due to confusion between flash of light and plash, splash. ] To strike and throw up large bodies of water from the surface; to splash. [ Obs. ] [ 1913 Webster ]

He rudely flashed the waves about. Spenser. [ 1913 Webster ]

Flashed glass. See Flashing, n., 3. [ 1913 Webster ]

2. A sudden and brilliant burst, as of wit or genius; a momentary brightness or show. [ 1913 Webster ]

The flash and outbreak of a fiery mind. Shak. [ 1913 Webster ]

No striking sentiment, no flash of fancy. Wirt. [ 1913 Webster ]

3. The time during which a flash is visible; an instant; a very brief period; as, I'll be back in a flash. [ 1913 Webster +PJC ]

The Persians and Macedonians had it for a flash. Bacon. [ 1913 Webster ]

4. A preparation of capsicum, burnt sugar, etc., for coloring and giving a fictitious strength to liquors. [ 1913 Webster ]

5. A lamp for providing intense momentary light to take a photograph; as, to take a picture without a flash.
Syn. -- flashbulb, photoflash, flash lamp, flashgun. [ WordNet 1.5 ]

6. Same as flashlight. [ informal ] [ PJC ]

7. (Journalism) A short news item providing recently received and usually preliminary information about an event that is considered important enough to interrupt normal broadcasting or other news delivery services; also called a news flash or bulletin. [ PJC ]

Flash light, or
Flashing light, a kind of light shown by lighthouses, produced by the revolution of reflectors, so as to show a flash of light every few seconds, alternating with periods of dimness. Knight. --
Flash in the pan, the flashing of the priming in the pan of a flintlock musket without discharging the piece; hence, sudden, spasmodic effort that accomplishes nothing. [ 1913 Webster ]

2. Wearing showy, counterfeit ornaments; vulgarly pretentious; as, flash people; flash men or women; -- applied especially to thieves, gamblers, and prostitutes that dress in a showy way and wear much cheap jewelry. [ 1913 Webster ]

Flash house, a house frequented by flash people, as thieves and whores; hence, a brothel. “A gang of footpads, reveling with their favorite beauties at a flash house.” Macaulay. [ 1913 Webster ]

2. (Engineering) A reservoir and sluiceway beside a navigable stream, just above a shoal, so that the stream may pour in water as boats pass, and thus bear them over the shoal. [ 1913 Webster ]

Flash wheel (Mech.), a paddle wheel made to revolve in a breast or curved water way, by which water is lifted from the lower to the higher level. [ 1913 Webster ]

2. An unusually vivid recollection of a prior experience, often one that is traumatic, such as scenes from combat or a criminal assault, or induced by hallucinogenic drugs such as LSD; when accompanied by hallucinations it is called flashback hallucinosis. [ PJC ]