Discount new beater (6)
I believe the answer is:
rebate
'discount' is the definition.
(rebating is a kind of discounting)
'new beater' is the wordplay.
'new' indicates an anagram.
'beater' anagrammed gives 'REBATE'.
(Other definitions for rebate that I've seen before include "Money back for beater" , "Money back, partial refund" , "Discount - tax return?" , "Return of, eg, tax" , "A bit taken off wood" .)