menstrual cycle

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The recurring cycle of physiological changes in the females of some animal species that is associated with reproductive fertility; especially the cycle in a human woman.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a recurring cycle (beginning at menarche and ending at menopause) in which the endometrial lining of the uterus prepares for pregnancy; if pregnancy does not occur the lining is shed at menstruation