historical Slavic language, ancestor of Belarusian, Rusyn, and Ukrainian; official, literary and spoken language of the Grand Duchy of Lithuania, Moldavian principality and East Slavic voivodeships of the Polish-Lithuanian Commonwealth
via Wikipedia infobox
Ruthenian (see also other names) was a written language used from the 14th to the 18th centuries within the East Slavic-speaking regions of the Grand Duchy of Lithuania and later the Polish-Lithuanian Commonwealth. Literary Ruthenian is considered to be a historical precursor to the modern Belarusian and Ukrainian languages (occasionally also to Rusyn), although neither standard language directly continues the Ruthenian written tradition.
Several linguistic issues are debated among linguists: various questions related to classification of literary and vernacular varieties of this language; issues related to meanings and proper uses of various endonymic (native) and exonymic (foreign) glottonyms (names of languages and linguistic varieties); questions on its relation to modern East Slavic languages, and its relation to Old East Slavic (the colloquial language used in Kievan Rus' in the 10th through 13th centuries).
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).