| olea | (n) evergreen trees and shrubs having oily one-seeded fruits, Syn. genus Olea |
| oleandra | (n) or family Polypodiaceae: tropical epiphytic or terrestrial ferns, Syn. genus Oleandra |
| olearia | (n) large genus of Australian evergreen shrubs or small trees with large daisylike flowers, Syn. genus Olearia |