δυσκέραστος
From LSJ
τὸ γὰρ εὖ πράττειν παρὰ τὴν ἀξίαν ἀφορμὴ τοῦ κακῶς φρονεῖν τοῖς ἀνοήτοις γίγνεται → undeserved success engenders folly in unbalanced minds
English (LSJ)
ον,
A hard to temper, φύσις πρὸς τὸ πιθανὸν δ. Plu.Dio 52; δύσμικτα καὶ δ. Id.2.754c.