Merriam-Webster's Collegiate® Dictionary, 11th Edition
OLIVE
I. noun
Etymology: Middle English, from Anglo-French, from Latin oliva, from Greek elaia
Date: 13th century
1. a Mediterranean evergreen tree ( Olea europaea of the family Oleaceae, the olive family) cultivated for its drupaceous fruit that is an important food and source of oil, any of various shrubs and trees resembling the olive, any of several colors resembling that of the unripe fruit of the olive tree that are yellowish green, an oval eminence on each ventrolateral aspect of the medulla oblongata,
II. adjective
Date: 1657
of the color olive or olive green, approaching olive in color or complexion