Like many attics (5)
I believe the answer is:
dusty
'like many attics' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dusty that I've seen before include "Dull (like a miller?)" , "In need of cleaning" , "Grubby" , "Neglected and in need of a clean" , "Boring" .)