Dishevelled robe on heavenly body (6)
I believe the answer is:
oberon
'heavenly body' is the definition.
Both the definition and answer are singular nouns.
Perhaps you can see an association between them that I don't see?
'dishevelled robe on' is the wordplay.
'dishevelled' indicates anagramming the letters.
'robe' with letters rearranged gives 'ober'.
'ober'+'on'='OBERON'
Can you help me to learn more?
(Other definitions for oberon that I've seen before include "Fairy king - no bore (anag)" , "Titania's king" , "Satellite" , "King of the fairies, husband of Titania" , "MND fairy king" .)