A pudding sent back cold (5)
I believe the answer is:
aloof
'cold' is the definition.
(both can mean distant)
'a pudding sent back' is the wordplay.
'pudding' becomes 'fool' (type of dessert).
'sent back' shows that the letters should be reversed in order.
'fool' reversed gives 'loof'.
'a'+'loof'='ALOOF'
(Other definitions for aloof that I've seen before include "Cool, distant" , "Blood deficiency" , "Haughty and distant like a fool" , "Withdrawn, supercilious" , "Remote in manner" .)