English books fall back (3)
I believe the answer is:
ebb
'fall back' is the definition.
(I've seen this before)
'english books' is the wordplay.
'english' becomes 'e' (abbreviation).
'books' becomes 'bb'.
'e'+'bb'='EBB'
(Other definitions for ebb that I've seen before include "Not to wax" , "Tidal retreat" , "Tidal outflow" , "Abate" , "recession" .)