French region welcoming a new source (10)
I believe the answer is:
provenance
'source' is the definition.
(provenance is a kind of source)
'french region welcoming a new' is the wordplay.
'french region' becomes 'provence' (I've seen this before).
'welcoming' means one lot of letters goes inside another (in sense of 'inviting in').
'a new' becomes 'an' (I've seen this in other clues).
'provence' placed around 'an' is 'PROVENANCE'.
(Other definitions for provenance that I've seen before include "Documented history" , "Source of painting" , "Origin of" .)