Related to heartless young man (4)
I believe the answer is:
told
'related' is the definition.
(I've seen this before)
'to heartless young man' is the wordplay.
'heartless' means to remove the middle letters.
'young man' becomes 'lad' (I've seen this before).
'lad' with its centre removed is 'ld'.
'to'+'ld'='TOLD'
(Other definitions for told that I've seen before include "Authorised - broadcast" , "Made an impact" , "Assured" , "Produced effect; related" , "Said" .)