Reply from Pep is not in newspaper (6)
I believe the answer is:
answer
'reply' is the definition.
('answer' can be a synonym of 'reply')
'from pep is not in newspaper' is the wordplay.
'from' indicates anagramming the letters (from the letters).
'is not in' is a deletion indicator.
'newspaper' with 'pep' taken out is 'nwsaer'.
'nwsaer' with letters rearranged gives 'ANSWER'.
(Other definitions for answer that I've seen before include "Acknowledge" , "Fulfil" , "Be satisfactory" , "It could give you a" , "See 9" .)