Carilyn is not a popular first name for women and an equally uncommon surname or last name for both men and women. (1990 U.S. Census)
Carilyn \c(a)-ril-yn, car(i)-lyn\ as a girl's name is a variant of Caroline (Old German), and the meaning of Carilyn is "free man". The baby name Carilyn sounds like Caralyn, Carlyn, Carolyn and Karilyn. Other similar baby names are Cailyn, Charilyn and Marilyn.