pendulum

/ˈpɛnd͡ʒələm/
noun
  1. 1

    A body suspended from a fixed support so that it swings freely back and forth under the influence of gravity, commonly used to regulate various devices such as clocks.

  2. 2

    A lamp, etc. suspended from a ceiling.

  3. 3

    A watch's guard-ring by which it is attached to a chain.

Source: https://en.wiktionary.org/wiki/pendulum