Source : Webster's Revised Unabridged Dictionary (1913)

Olive \Ol"ive\, n. [F., fr. L. oliva, akin to Gr. ?. See {Oil}.]
   1. (Bot.)
      (a) A tree ({Olea Europ[ae]a}) with small oblong or
          elliptical leaves, axillary clusters of flowers, and
          oval, one-seeded drupes. The tree has been cultivated
          for its fruit for thousands of years, and its branches
          are the emblems of peace. The wood is yellowish brown
          and beautifully variegated.
      (b) The fruit of the olive. It has been much improved by
          cultivation, and is used for making pickles. Olive oil
          is pressed from its flesh.

   2. (Zo["o]l.)
      (a) Any shell of the genus Oliva and allied genera; -- so
          called from the form. See {Oliva}.
      (b) The oyster catcher. [Prov.Eng.]

   3.
      (a) The color of the olive, a peculiar dark brownish,
          yellowish, or tawny green.
      (b) One of the tertiary colors, composed of violet and
          green mixed in equal strength and proportion.

   4. (Anat.) An olivary body. See under {Olivary}.

   5. (Cookery) A small slice of meat seasoned, rolled up, and
      cooked; as, olives of beef or veal.

   Note: Olive is sometimes used adjectively and in the
         formation of self-explaining compounds; as, olive
         brown, olive green, olive-colored, olive-skinned, olive
         crown, olive garden, olive tree, olive yard, etc.

   {Bohemian olive} (Bot.), a species of {El[ae]agnus} ({E.
      angustifolia}), the flowers of which are sometimes used in
      Southern Europe as a remedy for fevers.

   {Olive branch}.
      (a) A branch of the olive tree, considered an emblem of
          peace.
      (b) Fig.: A child.

   {Olive brown}, brown with a tinge of green.

   {Olive green}, a dark brownish green, like the color of the
      olive.

   {Olive oil}, an oil expressed from the ripe fruit of the
      olive, and much used as a salad oil, also in medicine and
      the arts.

   {Olive ore} (Min.), olivenite.

   {Wild olive} (Bot.), a name given to the oleaster or wild
      stock of the olive; also variously to several trees more
      or less resembling the olive.

Source : WordNet®

olive oil
     n : oil from olives