a camera shutter consisting of a rotating disk pierced with a slit that passes in front of the lens to expose the film or plate.
verb (used with or without object) 1. rototill.
noun 1. rototiller. 2. rotary plow.
noun, Machinery. 1. a valve that rotates continuously or through an arc to open and close.
noun, Aeronautics. 1. an airfoil that rotates about an approximately vertical axis, as that supporting a helicopter or autogiro in flight.