What does Gustus mean?
Gustus \g(u)-stus, gus-tus\ as a name for boys is of Scandinavian origin, and the meaning of the name Gustus is "royal staff; staff of the gods". Gustus is a variation of Gustave (Scandinavian): a royal name in Sweden.
Gustus is an uncommonly occurring first name for males but a very prominent last name for both adults and children (#52935 out of 150436, Top 35%). (2000 U.S. Census)
Popular variation forms of Gustus (#unlisted) are Gus, Guss, Gustaf, Gustav, Gustave and Gustavo (#482 in 2014). Usage of these boy names was at its peak during 1880-1889 (usage of 0.5053%) and has become much less since (usage 0.0863%, down 82.9%), with the versions Gus, Guss, Gustaf, Gustav and Gustave becoming somewhat dated. Gustavo (#482) is the most chic boy name here. Below is a graphed comparison of the usage of Gustus and related names. (Top 1000 Birth Names Statistics, 2014)
A recommended similar baby name is Justus. Like Gustus, this name is not frequently used.