The Collaborative International Dictionary of English v.0.48:

Entr'ee \En`tr['e]e"\, n. [F. See Entry.]
   1. A coming in, or entrance; hence, freedom of access;
      permission or right to enter; as, to have the entr['e]e of
      a house.
      [1913 Webster]

   2. (Cookery) In French usage, a dish served at the beginning
      of dinner to give zest to the appetite; in English usage,
      a side dish, served with a joint, or between the courses,
      as a cutlet, scalloped oysters, etc. [obsolescent]
      [1913 Webster]

   3. the dish which comprises the main course of a meal,
      especially in a restaurant; as, there were many entrees on
      the menu.
      [PJC]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "entree":
   access, adit, admission, admittance, antepast, boil, broil,
   casserole, course, cover, culinary masterpiece,
   culinary preparation, dessert, dish, entrance, entremets, entry,
   fry, grill, help, helping, import, importation, importing, in,
   income, incoming, infiltration, ingoing, ingress, ingression,
   input, insertion, insinuation, intake, interpenetration,
   introduction, introgression, intrusion, leakage, main dish,
   open arms, open door, opening, penetration, percolation, place,
   plate, portion, reception, roast, second helping, seepage, service,
   serving, side dish, way