Reprobate is the reverse of holy, right? (3)
I believe the answer is:
rip
'reprobate' is the definition.
(informal term for a fraud)
'the reverse of holy right?' is the wordplay.
'the reverse of' is a reversal indicator.
'holy' becomes 'pi' (I've seen this in other clues).
'right?' becomes 'r' (common abbreviation).
'pi'+'r'='pir'
'pir' back-to-front is 'RIP'.
'is' is the link.
(Other definitions for rip that I've seen before include "Rest in peace" , "Letters often seen on gravestone" , "dissolute character" , "Letters for the deceased" , "Letters appended to writing on gravestone" .)