The Collaborative International Dictionary of English v.0.48:

Entremets \En`tre*mets"\, n. sing. & pl. [F., fr. entre between
   + mets a dish, mess.]
   1. (Cookery) A side dish; a dainty or relishing dish usually
      eaten after the joints or principal dish; also, a
      sweetmeat, served with a dinner.
      [1913 Webster]

   2. Any small entertainment between two greater ones. [R.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

entremets
    n 1: a dish that is served with, but is subordinate to, a main
         course [syn: side dish, side order, entremets]