Critical; forming a turning-point or crisis

A period in a man's life corresponding to menopause.
Period during the life span when an important physiological change occurs, usually referring to menopause.
Critical time in a person's life; any critical turning point
Turning-point, especially in life of individual, generally reckoned at 21, 35, 49, 63 and 81 years of age; “change of life”, menopause.