What is the origin of the term “French kissing?” This article talks about the use of the word “French” in a variety of slang phrases. French letter, for instance, is a condom. The first use of the term French kissing appeared in the early 1920s, according to the article. That seems awfully late to me. Around that time other slang using the word “French” also appeared, because the French were seen as risque. Anyway, the article is from the ever-reliable Good Vibrations website. This summer tidbit is brought to you by the letter K.