Pronunciation: (flash'ing),[key] —n. 1. Building Trades.pieces of sheet metal or the like used to cover and protect certain joints and angles, as where a roof comes in contact with a wall or chimney, esp. against leakage.
2. the act of creating an artificial flood in a conduit or stream, as in a sewer for cleansing it.
3. Photog.,Motion Pictures.the process of increasing film speed by exposing undeveloped film briefly to a weak light source before using it or of exposing photographic printing paper to reduce contrast.