Flash  —v. 1 (cause to) emit a brief or sudden light; (cause to) gleam. 2 send or reflect like a sudden flame (eyes flashed fire). 3 a burst suddenly into view or perception (answer flashed upon me). B move swiftly (train flashed past). 4 a send (news etc.) By radio, telegraph, etc. B signal to (a person) with lights. 5 colloq. Show ostentatiously (flashed her ring). 6 slang indecently expose oneself. —n. 1 sudden bright light or flame, e.g. Of lightning. 2 an instant (in a flash). 3 sudden brief feeling, display of wit, etc. (flash of hope). 4 = *newsflash. 5 photog. = *flashlight 1. 6 mil. Coloured cloth patch on a uniform. 7 bright patch of colour. —adj. Colloq. Gaudy; showy; vulgar (flash car). [imitative]