means A regular, recurring pattern of movement, sound, or stress over time — the felt pulse that organizes music, speech, and motion.

from From the Greek 'rhythmos,' meaning measured flow or recurring movement, drawn from the root 'rhein,' to flow — the same current that runs through 'stream.' It traveled into Latin as 'rhythmus' and reached English through French. The notorious vowel-starved spelling is the Greek skeleton showing through: that lonely 'y' is the Greek upsilon, and the silent 'h' marks where Greek breathed.