There is a long English history of the phase “women of a certain age” because “it has a long history in French, where it refers to women of fortyish and thereabouts who are able to initiate boys and young men into the beauties of sexual encounters. The early use in English seems to be about spinsterhood, but the French meaning has nothing to do with marriage.”
In French, the phrase has erotically or sexually charged overtones. “It comes from a society where sexuality is freer,” Dr. Rubin notes, “and more understood as an important part of human life.”
The phrase in French is femmes d’une certaine age. The term, however, can apply to either sex. Without the certain, the phrase un homme d’un age translates literally as “a man of an age” and is defined in the Oxford-Hachette French Dictionary as “a man of advanced years.”
Une femme d’un certain âge is a French expression (“a woman of a certain age”) that suggests a positive attitude toward age, and alludes to the wisdom, experience, and elegance that we acquire along the way.