Janessa \j(a)-nessa, jan(es)-sa\ as a girl's name is pronounced ja-NESS-ah. It is of American origin. Blend of Jan or Jane and Vanessa. See also Ja-. Janessa has 3 variant forms: Janesse, Janissa and Jannessa. For more information, see also related names Janice and Jenessa. Baby names that sound like Janessa are Janeesa, Janessia, Janess, Jinessa and Jonessa. View a list of the 5 names that reference Janessa.