pendulum pendulum /ˈpɛndʒələm/

noun

1. () An apparatus consisting of an object mounted so that it swings freely under the influence of gravity  ( pendulum )
   an apparatus consisting of an object mounted so that it swings freely under the influence of gravity
    The pendulum of the grandfather clock swung back and forth, keeping time.
   The pendulum of the grandfather clock swung back and forth, keeping time.