Backward arrow on e-book brand (9)
I believe the answer is:
trademark
'brand' is the definition.
(I've seen this before)
'backward arrow on e-book' is the wordplay.
'backward' says the letters should be written in reverse.
'arrow' becomes 'dart' (I have seen 'Small arrow' mean 'dart' so perhaps 'arrow' could also mean 'dart').
'on' means one lot of letters go next to another.
'book' becomes 'mark' (I've seen this before).
'dart' written backwards gives 'trad'.
'trad'+'e'+'mark'='TRADEMARK'
(Other definitions for trademark that I've seen before include "Distinguishing feature" , "typical" , "Distinctive sign" , "distinctive characteristic" , "Brand - identifying symbol" .)