endoglossicPronunciation: /ˌɛndə(ʊ)ˈɡlɒsɪk/Definition of endoglossic adjective Linguistics denoting or relating to an indigenous language that is used as the first or official language in a country or community. Compare with exoglossic.Origin: 1980s: from endo-, Greek glōssa 'language, tongue', and -icendoglossic in other Oxford dictionaries Definition of endoglossic in the US English dictionary