Meaning of torsion pendulum

tor'sion pen"dulum

Pronunciation: [key]
— Horol. Horol.
  1. a pendulum the weight of which is rotated alternately in opposite directions through a horizontal plane by the torsion of the suspending rod or spring: used for clocks intended to run a long time between windings.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.