rhythm method(n = noun.act) calendar method, calendar method of birth control, rhythm, rhythm method of birth control - 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);
is a kind of natural family planning

alpha rhythm, atrioventricular nodal rhythm, basal body temperature method, basal body temperature method of family planning, beta rhythm, bradley method, bradley method of childbirth, calendar method, calendar method of birth control, cantering rhythm, cardiac rhythm, cascade method, circadian rhythm, contraceptive method, delta rhythm, eclectic method, experimental method, gallop rhythm, gram method, gram's method, heart rhythm, lamaze method, lamaze method of childbirth, leboyer method, leboyer method of childbirth, maieutic method, method, method acting, method of accounting, method of choice, method of fluxions, method of least squares, montessori method, musical rhythm, nodal rhythm, ovulation method, ovulation method of family planning, poetic rhythm, powder method, read method, read method of childbirth, relaxation method, rhythm, rhythm and blues, rhythm and blues musician, rhythm method of birth control, rhythm section, scientific method, sentence method, socratic method, speech rhythm, sprung rhythm, statistical method, straight-line method, straight-line method of depreciation, teaching method, theta rhythm, whole-word method, withdrawal method, word method