Cold about right? (9)
I believe the answer is:
heartless
'cold' is the definition.
(thesaurus)
'about right?' is the wordplay.
I cannot really see how this works, but
'about' could be 'a' (abbreviation in Chambers) and 'a' is found within the answer.
'right?' could be 'rt' (abbreviation as in Rt Hon- the Right Honourable) and 'rt' is present in the answer.
This explanation may well be incorrect...
(Other definitions for heartless that I've seen before include "Lacking all feelings" , "Without pity or feeling, being defective in cardiac way" , "Scrooge was" , "Callous" , "Lacking pity due to cardiac deficiency" .)