Noah Webster's New International Dictionary of the English Language
1. (v. i.) To burst or break forth with a sudden and transient flood of flame and light; as, the lighting flashes vividly; the powder flashed.
2. (v. i.) 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.
3. (v. i.) To burst forth like a sudden flame; to break out violently; to rush hastily.
4. (v. t.) To send out in flashes; to cause to burst forth with sudden flame or light.
5. (v. t.) 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.
6. (v. t.) To cover with a thin layer, as objects of glass with glass of a different color. See Flashing, n., 3 (b).
7. (n.) To trick up in a showy manner.
8. (n.) To strike and throw up large bodies of water from the surface; to splash.
9. (n.) A sudden burst of light; a flood of light instantaneously appearing and disappearing; a momentary blaze; as, a flash of lightning.
10. (n.) A sudden and brilliant burst, as of wit or genius; a momentary brightness or show.
11. (n.) The time during which a flash is visible; an instant; a very brief period.
12. (n.) A preparation of capsicum, burnt sugar, etc., for coloring and giving a fictitious strength to liquors.
13. (a.) Showy, but counterfeit; cheap, pretentious, and vulgar; as, flash jewelry; flash finery.
14. (a.) 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.
15. (n.) Slang or cant of thieves and prostitutes.
16. (n.) A pool.
17. (n.) 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.