| 1 | Ancient Greek | ῥυθμικός | — |
| 2 | Ancient Greek | ῥυθμός | a repeating, regular motion, vibration; measured... |
| 3 | Ancient Greek | ῥέω | I flow, stream, run, gush; I let flow, pour; I... |
| 4 | Proto-Indo-European | srew- | to flow, stream |
| 5 | Proto-Indo-European | ser- | to flow; to guard; to bind, to tie together |