Eric and Red reading in the encyclopedia about menopause
The word menopause literally means the permanent physiological, or natural, cessation of menstrual cycles, from the Greek roots 'meno' (month) and 'pausis' (a pause, a cessation). In layman's terms, menopause means the natural and permanent stopping of the monthly female reproductive cycles, and in humans this is usually indicated by a permanent absence of monthly periods, known as menstruation.
During the course of That 70's Show, Kitty shows signs of menopause until an episode during season five where she reveals that she has started menopause. It is referenced many times through out the series, often as a running joke.