rhythm

The word 'rhythm' originates from the Greek 'rhythmos', meaning a measured flow or movement, derived from the verb 'rhein', meaning 'to flow'. This Greek term passed into Latin as 'rhythmus' and then into Old French as 'rime' and 'ritme', before entering Middle English with its current spelling influenced by the Latin original. The core concept of a measured, flowing pattern has remained remarkably consistent from its ancient Greek origins, where it described the proportions in art, architecture, and poetry, to its modern applications in music, speech, and biological cycles.

The word 'rhythm' is a simplex loanword from Greek, entering English via Latin and Old French. It does not contain separable morphemes in its modern English spelling.