Rebuilt cart -- it is creative (8)
I believe the answer is:
artistic
'creative' is the definition.
(I've seen this before)
'rebuilt cart it is' is the wordplay.
'rebuilt' indicates anagramming the letters.
'cart'+'it'+'is'='cartitis'
'cartitis' with letters rearranged gives 'ARTISTIC'.
(Other definitions for artistic that I've seen before include "Aesthetic, creative" , "Fine-looking" , "I stir cat (anag.)" , "crafty!" , "Cultural" .)