A wife getting lines wrong (4)
I believe the answer is:
awry
'wrong' is the definition.
('awry' can be a synonym of 'wrong')
'a wife getting lines' is the wordplay.
'wife' becomes 'w'.
'getting' is a charade indicator (letters next to each other).
'lines' becomes 'ry' (abbreviation for railway).
'a'+'w'+'ry'='AWRY'
(Other definitions for awry that I've seen before include "Amiss, askew" , "Askance, askew" , "being on the wrong course" , "Amiss - distorted" , "Haywire" .)