(linguistics) A hypothetical, reconstructed language whence all the Slavic languages later descended.

Of or pertaining to the Proto-Slavic language / Of or pertaining to the people or nation that spoke Proto-Slavic

Of or relating to the East Slavs, their culture or language(s).

A subgrouping of the Slavic language family spoken mainly in Belarus, Russia and Ukraine. / (historical, rare) The Old East Slavic language.

Of or pertaining to the Balto-Slavic language, the people who spoke it or their culture.

The Proto-Balto-Slavic language, i.e. the common development stage between the Proto-Indo-European and the later Baltic and Slavic languages.

Alternative form of Church Slavonic

(Indo-European studies) The last phase of Proto-Slavic language, the Late Proto-Slavic. / (Indo-European studies, proscribed) Proto-Slavic

A subgrouping of the Slavic language family spoken mainly in the former Yugoslavia (Bosnia and Herzegovina, Croatia, North Macedonia, Montenegro, Serbia and Slovenia) and Bulgaria.

of or relating to South Slavic or the South Slavs