Cold aristocrat about to steal (5)
I believe the answer is:
creep
'steal' is the definition.
(synonyms)
'cold aristocrat about' is the wordplay.
'cold' becomes 'C' (abbreviation, eg on taps).
'aristocrat' becomes 'peer' (peer is a kind of aristocrat).
'about' shows that the letters should be reversed in order.
'peer' written backwards gives 'reep'.
'c'+'reep'='CREEP'
'to' acts as a link.
(Other definitions for creep that I've seen before include "Sycophant" , "jerk?" , "Obsequious person" , "narrow passage" , "wretch" .)