A sign of a good friendship is the ability to joke with each other and tease about things that only you know. This type of banter has a particular name: persiflage. It comes from the French word for “banter,” “persifler,” which itself is based on the word for “whistle,” “siffler.” We have myriad synonyms in English for “banter,” several of them also borrowed from French: “repartee,” “raillery,” “riposte,” “bon mots,” and “badinage.”