bodily function, bodily process, body process, activity - an organic process that takes place in the body; "respiratory activity"

ejaculation - the discharge of semen in males

excreting, excretion, voiding, elimination, evacuation - the bodily process of discharging waste matter

menses, menstruation, catamenia, menstruum, period, flow - the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause; "the women were sickly and subject to excessive menstruation"; "a woman does not take the gout unless her menses be stopped"--Hippocrates; "the semen begins to appear in males and to be emitted at the same time of life that the catamenia begin to flow in females"--Aristotle