Why is the ninth month called September?
also double-entendre, 1670s, from French (where it was rare and is now obsolete), literally "a twofold meaning," from entendre (now entente) "to hear, to understand, to mean." The proper Modern French phrase would be double entente, but the phrase has become established in English in its old form.
A word or expression that has two different meanings (in French, double-entendre means “double meaning”), one of which is often bawdy or indelicate. A double-entendre is found in this sentence: “A nudist camp is simply a place where men and women meet to air their differences.”