Discount English book with standard jacket (6)
I believe the answer is:
rebate
'discount' is the definition.
(I know that discount can be written as rebate)
'english book with standard jacket' is the wordplay.
'english book' becomes 'bate' (I am not sure about this - if you are sure you should believe this answer much more).
'with' means one lot of letters go next to another.
'standard' becomes 'rate' (I've seen this in other clues).
'jacket' says to hollow out the word (remove centre letters) (the letters worn by the word as a 'jacket' are use).
'rate' with its centre taken out is 're'.
'bate' put after 're' is 'REBATE'.
Can you help me to learn more?
(Other definitions for rebate that I've seen before include "Money refunded" , "A bit taken off wood" , "Sum paid back" , "(Eg, tax) refund" , "Discount - tax return?" .)