The Collaborative International Dictionary of English v.0.48:

maharani \maharani\ n.
   A great rani; a princess in India or the wife of a maharaja.
   [Also spelled maharanee.]
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

maharani
    n 1: a great rani; a princess in India or the wife of a maharaja
         [syn: maharani, maharanee]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "maharani":
   Kaiserin, begum, crown princess, czarina, empress, grand duchess,
   infanta, kumari, kunwari, malikzadi, princess, princesse, queen,
   queen consort, queen regent, queen regnant, raj-kumari, rani,
   shahzadi, sovereign princess, sovereign queen