Fromolea(“the olive tree or its fruit”) andoleum(“oil”), with-agineus suffix likely extracted fromfarrāgineus,tiliāgineus,similāgineus; with alternative forms afterfāginus,fabāginus. Not derived fromoleāgō(“oil mixed with the sweat of an athlete”).
oleāgineus (feminineoleāginea,neuteroleāgineum);first/second-declension adjective
First/second-declension adjective.