lingua franca

A term used in SOCIOLINGUISTICS, and often in everyday speech, to refer to an auxiliary LANGUAGE used to enable routine communication to take place between groups of people who speak different native languages; also sometimes called an interlingua. English is the world’s most common lingua franca, followed by French; but other languages are also widely used. In East Africa, for example, Swahili is the lingua franca; in many parts of West Africa, Hausa is used.