In haste, the word hieros usually meant sacred when used by the Fathers. Presbeteros meant then and means now a priest, like the parish priest. The more usual place to find the use of hieros is in hieromonk which means a monk who is a priest or hierodeacon, a monk who is a deacon. In more ancient Greek, interestingly enough, hieros was the word for a pagan priest, not presbyteros. Help any?
Seamole and Biblewonk had a roundabout discussion centered on the notion that since presbuteros also means "elder", perhaps the Church did not really have priests but rather, administrators and then wonks serving memorial lunch. Like the one I just had, with tequila.