Couple is last in prize list (7)
I believe the answer is:
itemise
'list' is the definition.
(to itemise is to create a list)
'couple is last in prize' is the wordplay.
'couple' becomes 'item' (a romantic couple are 'an item').
'last in' indicates one should take the final letters.
The last letter of 'prize' is 'e'.
'item'+'is'+'e'='ITEMISE'
(Other definitions for itemise that I've seen before include "List each thing separately" , "List exhaustively" , "Read off list of things one by one" , "Formulate a list" , "make inventory" .)