Wife to tear off for a drink (5)
I believe the answer is:
water
'a drink' is the definition.
(thesaurus)
'wife to tear off' is the wordplay.
'wife' becomes 'w'.
'to' says to put letters next to each other.
'off' is an anagram indicator.
'tear' is an anagram of 'ater'.
'w'+'ater'='WATER'
'for' acts as a link.
(Other definitions for water that I've seen before include "Aqua" , "Earth, air, fire partner" , "Drink - type of 1 across" , "Transparent liquid" , "Classical element" .)