Valets set out spotless one (6)
I believe the answer is:
vestal
'out spotless one' is the definition.
Both the definition and answer are adjectives. Maybe you can see a link between them that I don't see?
'valets set' is the wordplay.
'set' indicates an anagram (instruction to set the letters).
'valets' with letters rearranged gives 'VESTAL'.
Can you help me to learn more?
(Other definitions for vestal that I've seen before include "Like virgins of old" , "Valets for old Roman virgin" , "Chaste (Roman priestess)" , "Fat for candles/soap" , "Virgin charged with keeping alight the fire on the altar to a Roman goddess" .)