'meter' and 'rhythm' are termed in poetry and music. So what are their parallels? Their differences?
[p. 463] meter: the gathering of beats into regular groups
[p. 465] rhythm: the organization of time in music, dividing up long spans of time into smaller, more easily comprehended units
[p. 1590] meter
a pattern of stressed and unstressed syllables. (723–726, 771–775)
[p. 1592:] rhythm
in poetry, a pattern of stressed and unstressed sounds; in prose, some sort of recurrence (for example, of a motif) at approximately identical intervals. (717–718, 725)