Heavenly body set off, clothed by a revolutionary designer (8)
I believe the answer is:
asteroid
'heavenly body' is the definition.
(I know that asteroid is a type of minor planet)
'set off clothed by a revolutionary designer' is the wordplay.
'off' is an anagram indicator.
'clothed' becomes 'a' (I can't justify this - if you can you should believe this answer much more).
'by' is a charade indicator (letters next to each other).
'a revolutionary' shows that the letters should be reversed in order.
'designer' becomes 'dior' (dior is a designer brand).
'dior' backwards is 'roid'.
'set' with letters rearranged gives 'ste'.
'ste' after 'a' is 'aste'.
'aste'+'roid'='ASTEROID'
Can you help me to learn more?
(Other definitions for asteroid that I've seen before include "Small heavenly body" , "Ceres, say" , "Small rocky object orbiting the sun - store aid (anag)" , "Small rock orbiting the sun" , "Small celestial body moving around the sun" .)