Happy or joyful
Jocilynn is a modern American elaboration of Jocelyn. It traces back to the Germanic name Gautelen, which was derived from the name of a Germanic tribe, the Gauts, but later became associated with the Latin word 'jocundus', meaning merry or cheerful.
Less common today
Jocilynn isn't in the latest US Top 1000. It last peaked at #9,551 in 2010.
US births per 5-year period, 1990βpresent (SSA data).