Letter or note to devout holy man found by the French (7)
I believe the answer is:
epistle
'letter' is the definition.
(epistle is a kind of letter)
'note to devout holy man found by the french' is the wordplay.
'note' becomes 'e' (musical note**).
'to devout' becomes 'pi'.
'holy man' becomes 'st'.
'found by' means one lot of letters go next to another.
'the french' becomes 'le'.
'e'+'pi'+'st'+'le'='EPISTLE'
'or' is the link.
(Other definitions for epistle that I've seen before include "a for instance" , "communication" , "Letter, in the Bible perhaps" , "Specially long and formal letter" , "Biblical missive" .)