Crossword Genius

Sort of answer seemingly long unused (5)

Ross

I believe the answer is:

dusty

I'm a little stuck... Click here to teach me more about this clue!

'unused' is the definition.
Both the answer and definition are adjectives. Maybe you can see a link between them that I don't see?

I cannot understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for dusty that I've seen before include "Mr Miller" , "Miller - or answer, may be!" , "Old-fashioned" , "Covered in fine powder" , "In need of a spring clean" .)

I've seen this clue in the Evening Standard.
Want a hint initially instead of a full solution? Install my app