a. A widely cultivated evergreen tree (Olea europaea) native to the Mediterranean region, having fragrant white flowers, gray-green lance-shaped leathery leaves, and edible fruit with oil-rich flesh surrounding a hard stone.

b. The small oval fruit of this tree, usually changing in color from green to black as it ripens, used for food and as a source of oil.

c. Any of various similar or related plants, such as the Russian olive.