Spoil dissertation about Malta (6)
I believe the answer is:
pamper
'spoil' is the definition.
('pamper' can be a synonym of 'spoil')
'dissertation about malta' is the wordplay.
'dissertation' becomes 'paper' (I've seen this before).
'about' means one lot of letters goes inside another.
'malta' becomes 'm'.
'paper' enclosing 'm' is 'PAMPER'.
(Other definitions for pamper that I've seen before include "Spoil, over-indulge" , "Treat indulgently" , "Mollycoddle" , "baby" , "'Indulge, spoil (6)'" .)