MordvinPronunciation: /ˈmɔːdvɪn/ (also Mordva /ˈmɔːdva/)Definition of Mordvin noun (plural same, Mordvins, or Mordva) 1a member of a non-Russian people inhabiting Mordvinia. 2 [mass noun] the Finno-Ugric language of the Mordvin, which has two distinct dialects and over 1 million speakers altogether. adjective relating to the Mordvin or their language.