Characteristic art, transforming object (5)
I believe the answer is:
trait
'characteristic' is the definition.
(a trait is a quality or characteristic)
'art transforming object' is the wordplay.
'transforming' indicates anagramming the letters (I've seen 'transform' mean this).
'object' becomes 'it' (pronoun for an inanimate object).
'art' with letters rearranged gives 'tra'.
'tra'+'it'='TRAIT'
(Other definitions for trait that I've seen before include "Attribute, characteristic" , "Distinguishing characteristic of personality" , "Idiosyncrasy" , "Mannerism" , "Decorative band" .)