What does Jocelyn mean?

Jocelin (or Jocelyn) (died 1199) was a twelfth-century Cistercian monk and cleric who became the fourth Abbot of Melrose 
before becoming Bishop of Glasgow, Scotland. He was probably born in the 1130s
and in his teenage years became a monk of Melrose Abbey. 
He rose in the service of Abbot Waltheof, and by the time of the short abbacy of Waltheof's successor Abbot William, Jocelin had become prior. 
And he was led to the acquaintance and familiarity and friendship of many, and not only of the 
poor or the middling sort or the chief people of that land, but also of that King Cathwalain who was the ruler of that region. 

Jocelyn was revived in the 19th century and adopted as a feminine name, perhaps because it could be associated with names like Joyce 
(which also derives from Josse) combined with the -lyn ending.
Jocelyn Pronunciation of Jocelyn as a girls' name is pronounced JOSS-lin, JOSS-sa-lyn. 
It is of Old German origin, and the meaning of Jocelyn is "a member of the German tribe, the Gauts". 
From an Old French masculine name brought to Britain by the Normans in the form Joscelin, 
which was from Gautzelin, a pet name for a member of a Germanic tribe, the Gauts, who may have been the same as the Goths. 
The name may have been associated with pet forms of the name Josse, which was the French form of Judoc or Jodoc, 
probably from Celtic "jud" meaning "chief" or "lord". 
Saint Joducus, Prince and Hermit, body is incorrupt like Saint Rosa of Lima: saintscatholic.blogspot.com/2015/12/saint-judoc-saint-josse-saint-jost-or.html