Meaning of screw propeller

screw' propel"ler

Pronunciation: [key]
  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.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.