FLASH, noun

1. A sudden burst of light; a flood of light instantaneously appearing and disappearing; as a flash of lightning.

2. A sudden burst of flame and light; as instantaneous blaze; as the flash of a gun.

3. A sudden burst, as of wit or merriment; as a flash of wit; a flash of joy or mirth.

His companions recollect no instance of premature wit, no striking sentiment, no flash of fancy -

4. A short, transient state.

The Persians and Macedonians had it for a flash

5. A body of water driven by violence. [Local.]

6. A little pool. [Local.]

FLASH, verb intransitive

1. To break forth, as a sudden flood of light; to burst or open instantly on the sight, as splendor. It differs from glitter, glisten and gleam in 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. A diamond may glitter or glisten, but it does not flash flash differs from other words also in denoting suddenness of appearance and disappearance.

2. To burst or break forth with a flood of flame and light; as, the powder flashed in the pan. Flashing differs from exploding or disploding, in not being accompanied with a loud report.

3. To burst out into any kind of violence.

Every hour he flashes into one gross crime or other.

4. To break out, as a sudden expression of wit, merriment or bright thought.

FLASH, verb transitive

1. To strike up a body of water from the surface.

He rudely flashed the waves.

[In this sense I believe this word is not used in America.]

2. To strike or to throw like a burst of light; as, to flash conviction on the mind.