A lot of money if wife replaces husband in welfare (6)
I believe the answer is:
wealth
'welfare' is the definition.
(thesaurus)
'a lot of money if wife replaces husband' is the wordplay.
I cannot quite see how this works, but
'a' is found in the answer.
'money' could be 'l' (L can mean 'pounds') and 'l' is found in the answer.
'wife' could be 'w' and 'w' is found in the answer.
'husband' could be 'h' and 'h' is present in the answer.
This may be the basis of clue (or it may be nonsense).
'in' is the link.
(Other definitions for wealth that I've seen before include "Abundance of resources" , "Riches, worldly goods" , "was common under Cromwell" , "Possessions and resources" , "Assets" .)