"Blend of Jess and Lyn"
The name Jessilyn is commonly a female name.
Jessilyn is a modern American formation that joins Jess, the short form familiar from Jessica, with the -lyn ending that appears in many twentieth-century American girls' names. Its first appearance in US birth records, in 1968, fits that pattern rather than any older source language, and no meaning is attached to the combination itself.
The pronunciation of Jessilyn is JESS-ih-lin.
