Apathetic date appeared heartless (4)
I believe the answer is:
dead
'apathetic' is the definition.
(thesaurus)
'date appeared heartless' is the wordplay.
'date' becomes 'de' (I can't explain this - if you can you should give a lot more credence to this answer).
'heartless' means to remove the middle letters.
'appeared' with its centre removed is 'ad'.
'de'+'ad'='DEAD'
(Other definitions for dead that I've seen before include "Deceased; numb" , "Not functioning; numb" , "No longer alive" , "Gone to meet one's Maker" , "Devoid of life" .)