Noun menstruation has 1 sense

• menstruation(n = noun.process) catamenia, flow, menses, menstruum, period - 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"; "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"
is a kind of discharge, emission, expelling
has particulars: hypermenorrhea, menorrhagia, oligomenorrhea
Derived form verb menstruate₁