Gustavus \g(u)-sta-vus, gus-tavus\ as a boy's name is a variant of Gustave (Scandinavian), and the meaning of Gustavus is "royal staff; staff of the gods".

The baby name Gustavus sounds like Gustav and Gustavo. Other similar baby names are Gustus, Gustovo, Gustaof, Gustaff, Gustaf and Gustaaf.