The Collaborative International Dictionary of English v.0.48:

maharaja \maharaja\, maharajah \ma*ha*ra"jah\, n. [Skr.
   mah[=a]r[=a]ja; mahat great + r[=a]ja king.]
   A sovereign prince in India; a Hindu prince or king in India
   ranking above a raja; -- a title given also to other persons
   of high rank.
   [1913 Webster + WordNet 1.5]

WordNet (r) 3.0 (2006):

maharaja
    n 1: a great raja; a Hindu prince or king in India ranking above
         a raja [syn: maharaja, maharajah]