o- (1), op- | OEDoS

o- (1), op- (Prefix) "power to help" Not productive in Spanish. From Latin ops 'id.' From Proto-Italic *opi- 'id.' From Proto-Indo-European *h₃ep-i̯- "force." From *h₃ep- "to work," "to force." Indo-European Hellenic Ancient Greek ὄμπνη (ómpen) "corn" Indo-Iranian Sanskrit ápnas- "property," Young Avestan -haṇt- "rich" de Vaan, M. Etymological Dictionary of Latin and Other Italic Languages. BRILL. 2014. Real Academia Española. Diccionario de la lengua española. Online. 23rd ed. Madrid: Espasa Calpa. 2014. http://www.rae.es/. Sihler, A. New Comparative Grammar of Greek and Latin. Oxford University Press. 2008.