неопровержимый
From LSJ
Πυλάδη, σε γὰρ δὴ πρῶτον ἀνθρώπων ἐγὼ πιστὸν νομίζω καὶ φίλον ξένον τ' ἐμοί → Pylades for indeed I consider you, foremost among men, loyal and kind and a host to me (Euripides' Electra 82-83)
Russian > Greek
ἀκατάγνωστος, ἀνέλεγκτος, ἀνεξέλεγκτος, ἀνάλωτος, ἀκατάβλητος, δυσανταγώνιστος, ἄμαχος, ἄλυτος