Source : Webster's Revised Unabridged Dictionary (1913)

Nabob \Na"bob\ (n[=a]"b[o^]b), n. [Hind. naw[=a]b, from Ar.
   naw[=a]b, pl. of n[=a]["i]b a vicegerent, governor. Cf
   {Nawab}.]
   1. A deputy or viceroy in India; a governor of a province of
      the ancient Mogul empire.

   2. One who returns to Europe from the East with immense
      riches: hence, any man of great wealth. `` A bilious old
      nabob.'' --Macaulay.

Source : WordNet®

nabob
     n 1: a governor in India during the Mogual empire [syn: {nawab}]
     2: a wealthy man (especially one who made his fortune in the
        Orient)