Wish for wife to get a book (4)
I believe the answer is:
want
'wish for' is the definition.
(I've seen this in another clue)
'wife to get a book' is the wordplay.
'wife' becomes 'w' (abbreviation).
'to get' is a charade indicator (letters next to each other).
'book' becomes 'nt' (New Testament).
'w'+'a'+'nt'='WANT'
(Other definitions for want that I've seen before include "Desire to possess" , "poverty" , "Need or desire" , "'Wilful waste makes woeful . . . .'" , "Lack, desire" .)