Contract excluding wife’s tax (5)
I believe the answer is:
drain
'tax' is the definition.
(thesaurus)
'contract excluding wife's' is the wordplay.
'contract' becomes 'drawin'.
'excluding' is a deletion indicator.
'wife' becomes 'w'.
'drawin' with 'w' taken out is 'DRAIN'.
(Other definitions for drain that I've seen before include "Something using up resources" , "Waste channel/pipe" , "Gutter" , "Wasted down here" , "Waste channel" .)