Having it stops wife and husband (4)
I believe the answer is:
'having' is the definition.
(I've seen this in another clue)
'it stops wife and husband' is the wordplay.
'stops' indicates putting letters inside (stopping can mean blocking a gap).
'wife' becomes 'w' (abbreviation).
'and' is a charade indicator (letters next to each other).
'husband' becomes 'h' (abbreviation).
'it' going inside 'wh' is 'WITH'.
(Other definitions for with that I've seen before include "See 5" , "By means of" , "Possessing" , "In spite of" , "Alongside" .)