rhythm method

WordReference Random House Learner's Dictionary of American English © 2025

ˈrhythm ˌmeth•od, n. [uncountable]

1. Drugs a method of birth control in which sexual intercourse is not performed when ovulation is most likely to occur.

WordReference Random House Unabridged Dictionary of American English © 2025

rhythm′ meth′od, 

1. Drugs a method of birth control in which the couple abstain from sexual intercourse during the period when ovulation is most likely to occur. Cf. safe period. 

• 1935–40

Collins Concise English Dictionary © HarperCollins Publishers::

rhythm method noun

1. a method of controlling conception without the aid of a contraceptive device, by restricting sexual intercourse to those days in a woman's menstrual cycle on which conception is considered least likely to occur
   See also safe period