Desire, but with little morality (8)
I believe the answer is:
wantonly
'with little morality' is the definition.
(wanton can mean immoral or indecent)
'desire but' is the wordplay.
'desire' becomes 'want' (synonyms).
'but' becomes 'only' (I've seen this in another clue).
'want'+'only'='WANTONLY'
(Other definitions for wantonly that I've seen before include "Arbitrarily" , "in a provocative way" , "In a reckless unrestrained way" , "in lascivious way" , "in an immoral way" .)