Kind hearts absent in brief (4)
I believe the answer is:
sort
'kind' is the definition.
(synonyms)
'hearts absent in brief' is the wordplay.
'hearts' becomes 'h' (abbreviation used in card games e.g. bridge).
'absent in' is a deletion indicator.
'brief' becomes 'short' (synonyms).
'short' with 'h' taken out is 'SORT'.
(Other definitions for sort that I've seen before include "Arrange systematically" , "Put in order" , "'Variety, type (4)'" , "Arrange; category" , "Shuffle into desired sequence" .)