Frenchman and wife make a fresh start (5)
I believe the answer is:
renew
'make a fresh start' is the definition.
(to renew is refresh or restart)
'frenchman and wife' is the wordplay.
'frenchman' becomes 'rene' (common French name).
'and' says to put letters next to each other.
'wife' becomes 'w' (abbreviation).
'rene'+'w'='RENEW'
(Other definitions for renew that I've seen before include "Reinforce" , "Regenerate" , "Establish again" , "Renovate" , "Extend loan period" .)