Absence or cessation of menstruation. Amenorrhea is conventionally divided into primary and secondary amenorrhea. Primary amenorrhea -- menstruation never takes place. It fails to occur at puberty. Secondary amenorrhea -- menstruation starts but then stops. The absence of menstruation during pregnancy is a form of physiologic secondary amenorrhea, [..]

The absence or suppression of a woman's monthly menstrual period.

the absence of menstrual bleeding.

1804, Modern Latin, from Greek privative prefix a- "not" (see a- (3)) + men "month" (see moon (n.)) + rhein "to flow" (see rheum). Related: amenorrheal.

The absence or stopping of menstrual periods. 

Loss of the menstrual cycle. Considered part of the female athlete triad.

A lack of menstruation.

Absence of the menses due to causes other than pregnancy or advancing age.

noun. the lack of menses from the course of time between pubescence and menopause. Whenever menses do not start following pubescence, the state is regularly called primary amenorrhea. If menses cease, [..]

Amenorrhea is the absence of menstruation or having periods. It is classified once a woman has missed at least three consecutive periods or who has not started menstruating within the normal age range [..]

Absence of the menses due to causes other than pregnancy or advancing age.

(n) absence or suppression of normal menstrual flow

Absence of Menstruation.

Absence of menstruation.

 the absence of menstruation.

Absence or suppression of menstruation.  May occur as a side effect of some antidepressants and antipsychotic medications.  

The absence of a woman's monthly period not related to menopause. 

Refers to a woman who has never had a menstrual period.

(American spelling) amenorrhoea|lang=en

Lack of menstrual period for 6 months or more.

absence or failure of the menstrual periods.

Amenorrhea is a menstrual condition characterized by absent menstrual periods for more than three monthly menstrual cycles.