A scoundrel returned to snatch one crown (5)
I believe the answer is:
tiara
'one crown' is the definition.
(thesaurus)
'a scoundrel returned' is the wordplay.
'scoundrel' becomes 'rait' (I can't justify this - if you can you should give a lot more credence to this answer).
'returned' says the letters should be written backwards.
'a'+'rait'='arait'
'arait' in reverse letter order is 'TIARA'.
'to snatch' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
(Other definitions for tiara that I've seen before include "It might go to one's head" , "it goes to one's head!" , "Jewelled, ornamental headgear" , "expensive headwear" , "Jewelled headpiece" .)