Jack, the French Duke perhaps (5)
I believe the answer is:
noble
'duke perhaps' is the definition.
(I know that duke is a type of peer)
'jack the french' is the wordplay.
'jack' becomes 'nob' (term in the card game cribbage).
'the french' becomes 'le' ('the' in French).
'nob'+'le'='NOBLE'
(Other definitions for noble that I've seen before include "Having high moral character" , "Maybe count" , "Honourable ? aristocratic" , "Worthy" , "Of blue blood" .)