δυσαντιρρήτως

From LSJ

οἱ τοῖς πέλας ἐπιβουλεύοντες, λανθάνουσι πολλὰκις ὑφ' ἑτέρων τοῦτ' αὐτὸ πάσχοντες → when people plot against their neighbours, they fall victim to the same sort of plot themselves

Source

Russian (Dvoretsky)

δυσαντιρρήτως: неопровержимо (εἰρηκέναι Polyb.).