Column I covered in stucco (8)
I believe the answer is:
pilaster
'column' is the definition.
(pilaster is a kind of column)
'i covered in stucco' is the wordplay.
'covered in' is an insertion indicator.
'stucco' becomes 'plaster' (I've seen this before).
'i' inserted into 'plaster' is 'PILASTER'.
(Other definitions for pilaster that I've seen before include "Decorative column standing out from the fa?ade of a building" , "Piles tar into a form of column" , "Square column" , "Rectangular column projected from wall" , "Rectangular column support projecting slightly from a wall" .)