climacteric

climacteric \klahy-mak-TER-ik\, noun:

1. A critical period.
2. Physiology: a period of decrease of reproductive capacity in men and women, culminating, in women, in the menopause.
3. A year in which important changes in health, fortune, etc., are held by some theories to occur, as one's sixty-third year
4. The period of maximum respiration in a fruit, during which it becomes fully ripened.

Ernestine, who was the elder, asked one day, after her sister's visit had terminated in a climacteric of sisterly love, kisses, admonitions, and promises.
-- Jack London, The Grilling of Loren Ellery

I had reached an intellectual and artistic climacteric, a life climacteric of some sort.
-- Jack London, The Mutiny of the Elsinore

Climacteric originates in the Greek klimakter, "rung of a ladder."