perpetual motion perpetually • perpetual motion machine · · · Info · Definitions · Characters · · perpetual motion · · Text Common · · Latin · · Scripts 16 · · Length 6 · · Syllables Definitions · · · (noun) motion that continues indefinitely without any external source of energy; impossible in practice because of friction. Synonyms: perpetual motion. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 e latin small letter e U+0065 i latin small letter i U+0069 l latin small letter l U+006C m latin small letter m U+006D n latin small letter n U+006E o latin small letter o U+006F p latin small letter p U+0070 r latin small letter r U+0072 t latin small letter t U+0074 u latin small letter u U+0075