rhythm method

/ˌrɪðəm ˌmɛθəd/

Definitions of rhythm method

1. noun

   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)
   synonyms: calendar method, calendar method of birth control, rhythm, rhythm method of birth control

   type of:

   natural family planning

   any of several methods of family planning that do not involve sterilization or contraceptive devices or drugs; coitus is avoided during the fertile time of a woman's menstrual cycle