Someone who participates in a flash mob.

plural of blue flash

(roofing) Plies or strips of roof membrane material used to close-off and/or seal a roof at the horizonta-to-vertical intersections. Membrane base flashing covers the edge of the field membrane.

(waterways) A simple single-gate lock on a river or canal.

plural of flash lock

(roofing) an accessory flashing used to cover and/or seal soil pipe vents and other penetrations through a roof (sometimes referred to as roof jack or flashing boot).

(roofing) Individual pieces of sheet metal material used to flash walls, around chimneys, dormers and such projections along the slope of a roof. Individual pieces are overlapped and stepped up the vertical wall.

A formed metal counterflashing secured under a mechanical unit or skylight to cover and protect the upper edge of a base flashing and its associated fasteners.

A type of flashing used at roof-to-wall junctures and other roof-to-vertical plane intersections where an integral gutter is needed to handle runoff.

(roofing) A flashing located at the juncture of the top of a sloped roof and a vertical wall, chimney or steeper-sloped roof.