Eustace
The origin and history of Eustace.
Etymology
From the Old French form of Latin Eustathius, from Ancient Greek Εὐστάθιος (Eustáthios, “ancient name, also of Christian Saint”), from Ancient Greek εὐσταθής (eustathḗs, “steadfast, stable”). Or from εὔστᾰχῠς (eústăkhŭs, “fruitful”, literally “abundant in grain”), from εὖ (eû) + στάχυς (stákhus). Doublet of Ostap.