Meaning of worm gear

worm' gear"

Pronunciation: [key]
  1. a mechanism consisting of a worm engaging with and driving a worm wheel, the two axes usually being at right angles, used where a relatively low speed and a relatively large amplification of power are desired.
  2. Also calleda gear wheel driven by a worm.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.