Hallvor \ha-ll-vor\ as a boy's name is a variant of Halvard (Old Norse), and the meaning of Hallvor is "guardian of the rock".
The baby name Hallvor sounds like Halvor, Hallford, Halver, Halvar, Hallverd and Hallvard. Other similar baby names are Allvar, Ballfour, Balfor, Halford, Halverd, Heller, Hillyer, Hillier, Hiller, Ollivor and Olivor.