The story
- Proto-Indo-European*ser-?
- Proto-Indo-European*srew-
- Proto-Indo-European*sru-dʰ-mo-s
- Proto-Hellenic*hrutʰmós
- Ancient Greekῥῠθμός (rhŭthmós)
- Ancient Greekῥυθμικός (rhuthmikós)
- Englishrhythmic
- Proto-Indo-European*h₂el-
- Proto-Indo-European*h₂élisder.?
- Englishrhythmical
- English todayrhythmicality
From rhythmical + -ity.
Etymology from Wiktionary, CC BY-SA 4.0.