perpetual motion

1. 1.

   motion that continues indefinitely without any external source of energy; impossible in practice because of friction

   Broadermotion

Questions about perpetual motion

What does perpetual motion mean?

perpetual motion means "motion that continues indefinitely without any external source of energy; impossible in practice because of friction".

Is perpetual motion a common word?

perpetual motion is banded "Rare" — specialist or archaic — most readers will not have met it. The band comes from how often the word appears in a large corpus of everyday English, not from an editor's impression.