Josselyn /jos-se-lyn/ [3 sylls.] as a name for girls is of Old German derivation, and Josselyn means a member of the German tribe, the Gauts. Josselyn is a version of Jocelyn (Old German).Kreatif forms: Josselynna, Josselynni, Juselyn.osselyn /jos-se-lyn/ [3 sylls.] as a name for girls is of Old German derivation, and Josselyn means a member of the German tribe, the Gauts. Josselyn is a version of Jocelyn (Old German). Kreatif forms: Josselynna, Josselynni, Juselyn.