perpetuum mobile

Meaning

Noun

• A perpetual motion machine.
• Pieces of music, or parts of pieces, characterised by a continuous steady stream of notes, usually at a rapid tempo.
• Whole pieces, or large parts of pieces, which are to be played repeatedly, often an indefinite number of times.

Origin

• From Latin perpetuum (neutral inflection of perpetuus “perpetual”) + mōbile (neutrum of mōbilis “mobile, moving”), used together as a noun, thus literally meaning “perpetual mover”. Although often said to literally mean “perpetual motion”, the latter in Latin is mōtus perpetuus. A perpetuum mobile is a device that exhibits perpetual motion.