Lustrous (6)
I believe the answer is:
glossy
'lustrous' is the definition.
(I know that lustrous can be written as glossy)
This is all the clue.
(Other definitions for glossy that I've seen before include "Having shiny pages" , "Shiny on the surface" , "Shiny; type of magazine" , "Smooth, shiny" , "Lustrous" .)