Source : Webster's Revised Unabridged Dictionary (1913)

Marmalade \Mar"ma*lade\, n. [F. marmelade, Pg. marmelada, fr.
   marm['e]lo a quince, fr. L. melimelum honey apple, Gr. ? a
   sweet apple, an apple grafted on a quince; ? honey + ? apple.
   Cf. {Mellifluous}, {Melon}.]
   A preserve or confection made of the pulp of fruit, as the
   quince, pear, apple, orange, etc., boiled with sugar, and
   brought to a jamlike consistence.

   {Marmalade tree} (Bot.), a sapotaceous tree ({Lucuma
      mammosa}) of the West Indies and Tropical America. It has
      large obovate leaves and an egg-shaped fruit from three to
      five inches long, containing a pleasant-flavored pulp and
      a single large seed. The fruit is called marmalade, or
      natural marmalade, from its consistency and flavor.

Source : WordNet®

marmalade tree
     n : tropical American tree having wood like mahogany and sweet
         edible egg-shaped fruit; in some classifications placed
         in the genus Calocarpum [syn: {mammee}, {sapote}, {Pouteria
         zapota}, {Calocarpum zapota}]