SCREW n.
Compound, Foot, etc. -- A screw loose, something out of order, so that work is not done smoothly; as, there is a screw loose somewhere. H. Martineau. -- Endless, or perpetual screw, a screw used to give motion to a toothed wheel by the action of its threads between the teeth of the wheel; -- called also a worm. -- L…
SHAFT n.
The slender, smooth stem of an arrow; hence, an arrow. His sleep, his meat, his drink, is him bereft, That lean he wax, and dry as is a shaft. Chaucer. A shaft hath three principal parts, the stele [stale], the feathers, and the head. Ascham.