Persuade wife to go for express (3)
I believe the answer is:
say
'express' is the definition.
(thesaurus)
'persuade wife to go' is the wordplay.
'persuade' becomes 'sway' ('sway' can be a synonym of 'persuade').
'wife' becomes 'w'.
'to go' is a deletion indicator.
'sway' with 'w' taken away is 'SAY'.
'for' acts as a link.
(Other definitions for say that I've seen before include "by way of example" , "Verbalise" , "Articulate" , "Pronounce" , "Opportunity to influence < > state" .)