a common language used by speakers of different languages;
"Koine is a dialect of ancient Greek that was the lingua franca of the empire of Alexander the Great and was widely spoken throughout the eastern Mediterranean area in Roman times"
双语例句
Swahili is the principal lingua franca in East Africa. 东非的主要交际语是斯瓦希里语。
Once a lingua franca is established, it takes a long time to shift. 通用语言一旦形成，它的地位就不会在短时间内受到撼动。
