(n) the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause; ; --Hippocrates; --Aristotle, Syn. menstruum, menses, flow, period, catamenia, Example:the women were sickly and subject to excessive menstruation; a woman does not take the gout unless her menses be stopped; 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