P. and V. δύσμαχος, ἀνίκητος (Plato), Ar. and P. ἄμαχος (Plato), P. δυσπολέμητος, V. δυσπάλαιστος, ἀπρόσμαχος, ἀδήριτος.
impossible to deal with: P. and V. ἄπορος, ἀμήχανος (rare P.).
obstinate: see obstinate.
