screw propeller

noun

1. a rotary propelling device, as for a ship or airplane, consisting of a number of blades that radiate from a central hub and are so inclined to the plane of rotation as to tend to drive a helical path through the substance in which they rotate.

noun

1. an early form of ship’s propeller in which an Archimedes’ screw is used to produce thrust by accelerating a flow of water