Removed evidence of periods of French backsliding (6)
I believe the answer is:
erased
'removed evidence' is the definition.
'erased' can be an answer for 'removed' (I've seen this before). I am not certain of the 'evidence' bit.
'periods of french backsliding' is the wordplay.
'periods' becomes 'eras' (era is a kind of period).
'of french' becomes 'de' ('of' in French).
'backsliding' shows that the letters should be reversed in order.
'de' reversed gives 'ed'.
'eras'+'ed'='ERASED'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for erased that I've seen before include "Rubbed out, expunged" , "Removed by rubbing" , "Obliterated" , "'Wiped out, deleted (6)'" , "Red sea (anag)" .)