unassailable
From LSJ
English > Greek (Woodhouse)
adjective
Ar. and V. ἄμαχος, V. ἀπρόσμαχος; see invincible, unapproachable.
of an argument: Ar. ἀκατάβλητος.
unassailable by one's neighbours: P. ἄληπτος τοῖς πέλας (thno. 1, 37).
not liable to blame: P. and V. ἀνεπίληπτος.
have you met me on ground where my case is held by all to be unassailable? P. οὗ ἐγὼ μὲν ἀθῷος ἅπασι… ἐνταῦθα ἀπήντηκας; (Dem. 269).