Source : Webster's Revised Unabridged Dictionary (1913)

Tomato \To*ma"to\, n.; pl. {Tomatoes}. [Sp. or Pg. tomate, of
   American Indian origin; cf. Mexican tomail.] (Bot.)
   The fruit of a plant of the Nightshade family ({Lycopersicum
   esculentun}); also, the plant itself. The fruit, which is
   called also {love apple}, is usually of a rounded, flattened
   form, but often irregular in shape. It is of a bright red or
   yellow color, and is eaten either cooked or uncooked.

   {Tomato gall} (Zo["o]l.), a large gall consisting of a mass
      of irregular swellings on the stems and leaves of
      grapevines. They are yellowish green, somewhat tinged with
      red, and produced by the larva of a small two-winged fly
      ({Lasioptera vitis}).

   {Tomato sphinx} (Zo["o]l.), the adult or imago of the tomato
      worm. It closely resembles the tobacco hawk moth. Called
      also {tomato hawk moth}. See Illust. of {Hawk moth}.

   {Tomato worm} (Zo["o]l.), the larva of a large hawk moth
      ({Sphinx, or Macrosila, quinquemaculata}) which feeds upon
      the leaves of the tomato and potato plants, often doing
      considerable damage. Called also {potato worm}.

Source : WordNet®

tomato
     n 1: mildly acid red or yellow pulpy fruit eaten as a vegetable
     2: native to South America; widely cultivated in many varieties
        [syn: {love apple}, {tomato plant}, {Lycopersicon
        esculentum}]
     [also: {tomatoes} (pl)]

tomatoes
     See {tomato}