The Collaborative International Dictionary of English v.0.48:

Fianc'ee \Fi`an`c['e]e"\, n. [F.]
   A betrothed woman; the woman to whom one is betrothed.
   [1913 Webster +PJC]

WordNet (r) 3.0 (2006):

fiancee
    n 1: a woman who is engaged to be married [syn: fiancee,
         bride-to-be]