Frenchman and wife begin again (5)
I believe the answer is:
renew
'begin again' is the definition.
(I've seen this before)
'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 "Take up again" , "what regeneration will do" , "modernise" , "Regenerate" , "Restore to original state" .)