"Blend of Jess and Lynn"
The name Jeslynn is commonly a female name from the "American" origin.
Jeslynn is a modern American blend of the element Jess, familiar from Jessica and Jessie, and the suffix Lynn. The name does not appear in United States birth records before 1995, which fits a formed name rather than one inherited from an earlier tradition.
The pronunciation of Jeslynn is JESS-lin.