Istrus
From LSJ
τὸ γὰρ εὖ πράττειν παρὰ τὴν ἀξίαν ἀφορμὴ τοῦ κακῶς φρονεῖν τοῖς ἀνοήτοις γίγνεται → undeserved success engenders folly in unbalanced minds
Latin > French (Gaffiot 2016)
(1) Istrus, a, um, de l’Istrie : Mart. 12, 63, 2.
(2) Istrus, ī, f., c. Istropolis : Anton.