He really likes to have pounds to spare (5)
I believe the answer is:
lover
'he really likes' is the definition.
(I've seen this before)
'pounds to spare' is the wordplay.
'pounds' becomes 'l' (L can represent the monetary pound).
'to spare' becomes 'over' (left over).
'l'+'over'='LOVER'
'to have' acts as a link.
(Other definitions for lover that I've seen before include "One enjoys" , "Sweetheart" , "'Lady Chatterley's - - ' by D H Lawrence" , "He really likes" , "finished litre first" .)