The Collaborative International Dictionary of English v.0.48:

Dessert \Des*sert"\, n. [F., fr. desservir to remove from table,
   to clear the table; pref. des- (L. dis-) + servir to serve,
   to serve at table. See Serve.]
   A service of pastry, fruits, or sweetmeats, at the close of a
   feast or entertainment; pastry, fruits, etc., forming the
   last course at dinner.
   [1913 Webster]

         "An 't please your honor," quoth the peasant,
         "This same dessert is not so pleasant."  --Pope.
   [1913 Webster]

   Dessert spoon, a spoon used in eating dessert; a spoon
      intermediate in size between a teaspoon and a tablespoon.


   Dessert-spoonful, n., pl. Dessert-spoonfuls, as much as a
      dessert spoon will hold, usually reckoned at about two and
      a half fluid drams.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dessert
    n 1: a dish served as the last course of a meal [syn: dessert,
         sweet, afters]

Moby Thesaurus II by Grady Ward, 1.0:

31 Moby Thesaurus words for "dessert":
   ambrosia, antepast, bonne bouche, cate, choice morsel, course,
   cover, dainty, delicacy, dish, entree, entremets, goody, help,
   helping, kickshaw, manna, morsel, nectar, place, plate, portion,
   pudding, savory, second helping, service, serving, sweet, tidbit,
   titbit, treat