Jocelyn

The historical form Gaudelenus is probably a reading error. It is found in Förstemann (1900) with the remark: Gaudelenus, bisch. V. Lerida (Spanien) a. 653; but Wikipedia lists the name of the bishop of Lleida (Catalan for Lerida) as Gandeleno (German W.) or Gandelè (English W, citing the Catalan form of the name). So it seems that modern consensus reads a letter N before the D and not a U.

---

I was not able to find other people named Gaudelenus.

---

P.S. This does not invalidate the rest of the etymology section, forms with t/ts/c/z are amply attested, only Gaudelenus should be deleted. [noted -ed]

A derivation from *Gautselin is inaccurate—the name was formed in the late Frankish period from Gois-/Gaus-, the Latinized and West Frankish derivative of Gaut in onomastic use (compare Cos- from Gaut- in Lombard names) and the Romance diminutive suffixes -el and -inus. It is then a Frankish/OF diminitive based on names such as Goisfridus (Geoffrey), Goisbertus, Goismerus etc., rather than an ancient Germanic name based directly on Gaut. Further Gauselin and the Gauselm (Germanic Gaut-helm) and their derivatives are frequently confused in the recorded texts, Goiselmus for Goiselinus and vice versa. [noted -ed]

Jocelyn is the medieval English name that means joy!

Could it be associated with the Gaelic descriptive surname Joyce/Seoige (from the Welsh word, "sais", meaning Saxon or English), with the diminutive -lin on the end?

According to the Dictionary of First Names, when Jocelyn entered English the spelling was changed because Joscelin was taken as a double diminuative (with the Old French suffixes '-el' and '-in') of Josce (Joyce).