Amenorrhea

n. absence of menstruation, suppression of menstruation

Amenorrhoea (BE), amenorrhea (AmE), or amenorrhœa, is the absence of a menstrual period in a woman of reproductive age. Physiologic states of amenorrhoea are seen during pregnancy and lactation (breastfeeding), the latter also forming the basis of a form of contraception known as the lactational amenorrhea method. Outside of the reproductive years there is absence of menses during childhood and after menopause.
See more at Wikipedia.org...

The absence of menstrual periods is called amenorrhea. Primary amenorrhea is the failure to start having a period by the age [more]Amenorrhea - Community and Resources

Noun
1. absence or suppression of normal menstrual flow
(synonym) amenorrhoea, amenia
(hypernym) symptom
(hyponym) primary amenorrhea

The absence (especially the abnormal absence) or abnormal stoppage of menses.