The artist conceals compassion (5)
I believe the answer is:
heart
'compassion' is the definition.
(I've seen this before)
'the artist conceals' is the wordplay.
'conceals' indicates the answer is hidden within the clue.
'HEART' can be found hidden inside 'the artist'.
(Other definitions for heart that I've seen before include "show enthusiasm" , "Muscular organ for blood circulation" , "Cardiac organ" , "Central part" , "Cardiac courage" .)