Grainnia \gra(in)-nia\ as a girl's name is a variant of Grainne (Irish, Gaelic), and the meaning of Grainnia is "love".

The baby name Grainnia sounds like Grania, Carinna, Corinna, Corrinna, Gerianna, Karaina, Karinna and Korinna. Other similar baby names are Urainia, Brinna, Erinna, Frannie, Franni, Frania, Gaiana, Granata, Grazyna, Grazina, Grazia, Gratiana, Gratia, Gracina, Graciana, Gracia, Granada, Guinna, Gaenna, Gwinna, Orania and Urania.