ˈsaɪkəl ˈɹɪ.ð(ə)m natural family planning 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) recurring at regular intervals the arrangement of spoken words alternating stressed and unstressed elements the rhythm of Frost's poetry the basic rhythmic unit in a piece of music the piece has a fast rhythm the conductor set the beat an interval during which a recurring sequence of events occurs the never-ending cycle of the seasons (architecture) the repetitive use of a group of visual elements to establish a recognizable pattern