Answer: pendulums

AnswerCrossword Clue
PENDULUMSParts of grandfather clocks.
PENDULUMSParts of metronomes.
PENDULUMSSwingers
pendulumsUsed to refer to the tendency of a situation or state of affairs to oscillate regularly between one extreme and another
pendulumsPENDULUM, a type of free swinging body
pendulumsA weight hung from a fixed point so that it can swing freely backward and forward, esp. a rod with a weight at the end that regulates the mechanism of a clock