Pendulum

How to spell pendulum

8 letters · 3 syllables

How to pronounce pendulum

Say the part in capitals loudest.

What does pendulum mean?

1. nounA weight suspended from a fixed point so that it can swing freely back and forth, often used to regulate a clock.

Pendulum in a sentence

• The brass pendulum in the grandfather clock swung steadily through the night.

• The science teacher timed how long each pendulum took to complete one full swing.

Where does pendulum come from?

Language of origin: Latin

The word comes directly from the Latin pendulum, the neuter form of the adjective pendulus, meaning 'hanging down' or 'swinging'. That adjective was built on the verb pendere, which literally meant 'to hang', the same root that gives us 'pendant', 'suspend', and 'depend' (to hang from something). It entered English in the seventeenth century as a scientific term, just as Galileo and later Christiaan Huygens were studying the regular swing of a weighted cord for use in timekeeping. By the 1660s 'pendulum' described the swinging weight that regulates a clock, and the meaning soon broadened to any heavy body that swings freely from a fixed point. The spelling keeps the Latin -ulum ending intact, which is the part writers most often stumble over, since the unstressed middle syllable sounds like a vague schwa rather than the 'u' that is actually written.

How the word is built

• pend (Latin pendere: to hang)
• -ulum (Latin diminutive/noun suffix)