Discolored spot (5)
I believe the answer is:
stain
(Other definitions for stain that I've seen before include "Discolouring mark" , "Tarnish" , "Discoloured patch" , "Unsightly mark" , "Smear" .)
I believe the answer is:
stain
(Other definitions for stain that I've seen before include "Discolouring mark" , "Tarnish" , "Discoloured patch" , "Unsightly mark" , "Smear" .)