Maintain quiet modesty's awfully perverse (8)
I believe the answer is:
preserve
'maintain quiet modesty's' is the definition.
'preserve' can be an answer for 'maintain' (preserving is a kind of maintaining). I'm not certain of the 'quiet modesty's' bit.
'awfully perverse' is the wordplay.
'awfully' is an anagram indicator.
'perverse' is an anagram of 'PRESERVE'.
Can you help me to learn more?
(Other definitions for preserve that I've seen before include "Prevent from rotting" , "Maintain in unaltered condition" , "Keep alive; jam" , "Toast option" , "Look after" .)