Πολλοῖς ὁ Δαίμων, οὐ κατ' εὔνοιαν φέρων, / Μεγάλα δίδωσιν εὐτυχήματ' ... (Euripides) → God brings great good fortune to many, not out of good will,...
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.).