The Collaborative International Dictionary of English v.0.48:

Sapodilla \Sap`o*dil"la\, n. [Sp. zapote, sapotillo, zapotillo,
   Mexican cochit-zapotl. Cf. Sapota.] (Bot.)
   A tall, evergeen, tropical American tree (Achras Sapota);
   also, its edible fruit, the sapodilla plum. [Written also
   sapadillo, sappadillo, sappodilla, and zapotilla.]
   [1913 Webster]

   Sapodilla plum (Bot.), the fruit of Achras Sapota. It is
      about the size of an ordinary quince, having a rough,
      brittle, dull brown rind, the flesh being of a dirty
      yellowish white color, very soft, and deliciously sweet.
      Called also naseberry. It is eatable only when it begins
      to be spotted, and is much used in desserts.
      [1913 Webster]

WordNet (r) 3.0 (2006):

sapodilla
    n 1: large tropical American evergreen yielding chicle gum and
         edible fruit; sometimes placed in genus Achras [syn:
         sapodilla, sapodilla tree, Manilkara zapota, Achras
         zapota]
    2: tropical fruit with a rough brownish skin and very sweet
       brownish pulp [syn: sapodilla, sapodilla plum, sapota]