Rising graffiti artist concealed distinguishing feature (5)
I believe the answer is:
trait
'distinguishing feature' is the definition.
(I've seen this before)
'rising graffiti artist concealed' is the wordplay.
'rising' says the letters should be written backwards (going up in a down clue).
'concealed' says the answer is hidden in the clue.
'tiart' is hidden within 'graffiti artist'.
'tiart' backwards is 'TRAIT'.
(Other definitions for trait that I've seen before include "Feature of personality" , "Habit" , "Mannerism" , "Characteristic or distinguishing quality" , "Attribute, characteristic" .)