A method of birth control in which a couple abstains from intercourse during the days in which the woman is most likely to be fertile.
A regular movement or beat.
Measured time or movement; one single event that is repeated; regular occurrence of an impulse, such as the cardiac rhythm.
The relative measurement of an impulse or activity in relation to time; regularity of action.
A measured time or movement; regularity of occurrence of action or function.
A regular pulsation or recurrent pattern of movement in a design.
An occurrence that happens at consistent intervals.