What does Selwyn mean?
Selwyn /sel-wyn/ [2 sylls.] as a boys' name is of Old English origin, and the meaning of Selwyn is "manor-friend". Also a derivation from Silvanus. Mostly 19th-century use.
How popular is Selwyn?
Selwyn is an uncommon first name for males but a very popular last name for both adults and children (#48963 out of 150436, Top 33%). (2000 U.S. Census)
The only popular alternative form of Selwyn (outside Top 1000) is Silvio. Adoption of this boy name was at its highest during 1920-1929 (usage of 0.201%) and has become significantly lower since, with Silvio becoming less fashionable. Below is a charted comparison of the usage of the boy name Selwyn and associated names. (Top 1000 Birth Names Records, 2014)