Omaha2Pronunciation: /ˈəʊməhɑː/Definition of Omaha noun (plural same or Omahas) 1a member of an American Indian people of NE Nebraska. 2 [mass noun] the Siouan language of the Omaha, now all but extinct. adjective relating to the Omaha or their language. Origin:from Omaha umonhon 'upstream people'Omaha in other Oxford dictionaries Definition of Omaha in the US English dictionary