Graeco-Armenian

Graeco-Armenian (also Helleno-Armenian) is the hypothetical common ancestor of the Greek and Armenian languages that postdates the Proto-Indo-European language (PIE). Its status is comparable to that of the Italo-Celtic grouping: each is widely considered plausible without being accepted as established communis opinio. The hypothetical Proto-Graeco-Armenian stage would need to date to the 3rd millennium BC, only barely differentiated from either late PIE or Graeco-Armeno-Aryan.

The Graeco-Armenian hypothesis originated in 1924 with Holger Pedersen, who noted that the number of Greek-Armenian lexical cognates is greater than that of agreements between Armenian and any other Indo-European language. During the mid-to-late 1920s, Antoine Meillet further investigated morphological and phonological agreements, postulating that the parent languages of Greek and Armenian were dialects in immediate geographical proximity in the parent language. Meillet's hypothesis became popular in the wake of his Esquisse d'une grammaire comparée de l'arménien classique.G. R. Solta does not go as far as postulating a Proto-Graeco-Armenian stage, but he concludes that considering both the lexicon and morphology, Greek is clearly the dialect most closely related to Armenian.Eric Hamp supports the Graeco-Armenian thesis, anticipating even a time "when we should speak of Helleno-Armenian" (meaning the postulate of a Graeco-Armenian proto-language).James Clackson is again more reserved, holding the evidence in favour of a positive Graeco-Armenian sub-group to be inconclusive and tends to include Armenian into a larger Graeco-Armeno-Aryan family.

Evaluation of the hypothesis is tied up with the analysis of the poorly attested Phrygian language. While Greek is attested from very early times, allowing a secure reconstruction of a Proto-Greek language dating to circa 3rd millennium BC, the history of Armenian is opaque. It is strongly linked with Indo-Iranian languages; in particular, it is a satem language.

...
Wikipedia