The Collaborative International Dictionary of English v.0.48:

Inamorata \In*a`mo*ra"ta\, n. [It. innamorata, fem., innamorato,
   masc., p. p. of innamorare to inspire with love. See
   Enamor.]
   A woman in love; a mistress. "The fair inamorata."
   --Sherburne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

inamorata
    n 1: a woman with whom you are in love or have an intimate
         relationship

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "inamorata":
   Dulcinea, beloved, best girl, doxy, dream girl, flame, gill, girl,
   girl friend, honey, jill, jo, lady, lady love, ladylove, lass,
   lassie, lover, mistress, old lady, paramour, steady, sweetheart,
   sweetie, truelove, woman