noun
[ U ] the ancient language on which all Indo-European languages are thought to be based. There are no written records of Proto-Indo-European, but experts have tried to construct it from the evidence of modern languages.
noun
[ U ] the ancient language on which all Indo-European languages are thought to be based. There are no written records of Proto-Indo-European, but experts have tried to construct it from the evidence of modern languages.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005