Indifferent about elderly (4)
I believe the answer is:
cold
'indifferent' is the definition.
(thesaurus)
'about elderly' is the wordplay.
'about' becomes 'c' (abbreviation for circa).
'elderly' becomes 'old' (similar in meaning).
'c'+'old'='COLD'
(Other definitions for cold that I've seen before include "Unfeeling" , "Unsympathetic" , "Unemotional; wintry" , "Lacking emotion" , "complaint" .)