(meteorology, astronomy) A rare phenomenon observed in morning or evening when the sun is crossing or immediately below the horizon, in which a momentary flash or ray of green light appears above the upper rim of the solar disk, caused by refraction of light in the atmosphere.

(meteorology, astronomy) A very rare phenomenon observed in the morning or evening when the sun is crossing or immediately below the horizon, in which a momentary flash of blue light appears above the upper rim of the solar disk, caused by refraction of light in the atmosphere.

(countable) A fictional story that is briefer than typical short stories. / (uncountable) The genre of such stories.

plural of green flash

(physics) The lowest temperature at which a liquid can form an ignitable mixture in air near the surface of the liquid. / (figuratively) A hotspot; a dangerous place of violent political unrest.

A group of people who rapidly assemble, perform an unusual and seemingly pointless act, and then quickly disperse.

plural of flash mob

Alternative form of flashcard

plural of flash card

Alternative form of flashcrowd / A large audience for a sporting event that is unexpected because of large numbers of game-day ticket sales rather than advance tickets. / A crowd that forms suddenly.