Pure or alert
Casyn is a modern American invention, likely created as a phonetic variation of Cason or a blend of Casey and Mason. While its roots are obscure, it is often associated with the Greek name Katherine, meaning pure, or the Irish surname Casey, meaning vigilant or alert.
About 18 boys were named Casyn in 2025.
US births per 5-year period, 1990–present (SSA data).
