Polish, shine (4)
I believe the answer is:
buff
This clue is a double definition.
'polish' is the first definition.
(I know that buff is a type of polish)
'shine' is the second definition.
(I know that buff is a type of shine)
(Other definitions for buff that I've seen before include "nude?" , "Pale yellow" , "Yellowish-beige; expert" , "Yellowish colour - polish - expert" , "light shade" .)