Meaning and Name Origin
Sylvanus is an uncommon first name for males. Sylvanus is a rare surname too for both adults and children. (2000 U.S. Census)
Below is a charted comparison of the popularity of the boy name Sylvanus and affiliated names. Silvio is the only prominent related form of Sylvanus (#unlisted). Adoption of this boy name was at its highest during 1920-1929 and is now much less, with the form Silvio becoming less fashionable. (Top 1000 Birth Names Records, 2014)
A suggested similar baby name is Sylvan. Like Sylvanus, this name is not frequently used.