Oversight over in Prince's palace (5)
I believe the answer is:
lapse
'oversight' is the definition.
(I know that lapse can be written as lapse)
'over in prince's palace' is the wordplay.
'over' says the letters should be written in reverse.
'in' indicates the answer is hidden within the clue.
'espal' is hidden in the letters of 'princes palace'.
'espal' reversed gives 'LAPSE'.
(Other definitions for lapse that I've seen before include "Slight error due to forgetfulness" , "Brief (memory) failure" , "Fall from grace" , "Negligence" , "unguarded moment" .)