Reply tripe, so slammed (7)
I believe the answer is:
riposte
'reply' is the definition.
(riposte is a kind of reply)
'tripe so slammed' is the wordplay.
'slammed' indicates an anagram.
'tripe'+'so'='tripeso'
'tripeso' with letters rearranged gives 'RIPOSTE'.
(Other definitions for riposte that I've seen before include "Reply, response" , "Reply, retort" , "Quick sharp reply" , "Quick clever reply" , "Repartee; quick thrust (fencing)" .)