Rionnah \ri(on)-nah\ as a girl's name is a variant of Riona (Irish, Gaelic), and the meaning of Rionnah is "queenly".
The baby name Rionnah sounds like Rionna, Reannah, Rinah, Rianna and Ronna. Other similar baby names are Rionnagh, Liannah, Dionna, Diannah, Fionna, Gionna, Yionna, Kionna, Kionah, Nonnah, Rionagh, Rionach and Tionna.