Marked with blotches (7)
I believe the answer is:
mottled
'marked with blotches' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for mottled that I've seen before include "Blotchy" , "Marked with spots" , "with variable effect" , "Having blotches of colour" , "Marked with streaks or blotches" .)