lingua franca
noun [ C usually singular ] uk/ˌlɪŋ.ɡwə ˈfræŋ.kə/ us/ˌlɪŋ.ɡwə ˈfræŋ.kə/
（母语不同的人交流用的）通用语，混合语
a language used for communication between groups of people who speak different languages
The international business community sees English as a lingua franca. 国际商界将英语视为通用语言。