Wilfully desire no more than … (8)
I believe the answer is:
'wilfully' is the definition.
(both can mean deliberately or provocatively)
'desire no more than' is the wordplay.
'desire' becomes 'want' (synonyms).
'no more than' becomes 'only' (eg 'only 10' means 'no more than 10').
(Other definitions for wantonly that I've seen before include "in an extravagant way" , "in an immoral way" , "in lascivious way" , "in a provocative way" , "In a reckless unrestrained way" .)