Sinnie \s(in)-nie\ as a girl's name is a variant of Cynthia (Greek), and the meaning of Sinnie is "from Mount Kynthos".
The baby name Sinnie sounds like Sannie, Cinnie, Sonnie and Sunnie. Other similar baby names are Vinnie, Binnie, Sindie, Dinnie, Jinnie, Ginnie, Winnie, Minnie, Linnie, Sidnie and Sivnie.