1. (noun)rhythm, beat, musical rhythm the basic rhythmic unit in a piece of music "the piece has a fast rhythm"; "the conductor set the beat"
2. (noun)rhythm, regular recurrence recurring at regular intervals
3. (noun)cycle, rhythm, round an interval during which a recurring sequence of events occurs "the never-ending cycle of the seasons"
4. (noun)rhythm, speech rhythm the arrangement of spoken words alternating stressed and unstressed elements "the rhythm of Frost's poetry"
5. (noun)rhythm method of birth control, rhythm method, rhythm, calendar method of birth control, calendar method naturalfamilyplanning in which ovulation is assumed to occur 14 days before the onset of a period (the fertile period would be assumed to extend from day 10 through day 18 of her cycle)