Ready to receive East German response (7)
I believe the answer is:
riposte
'response' is the definition.
(riposte is a kind of response)
'ready to receive east german' is the wordplay.
'ready' becomes 'ripe' ('ripe' can be similar in meaning to 'ready').
'to receive' is an insertion indicator.
'east german' becomes 'ost' ('east' in German).
'ripe' placed around 'ost' is 'RIPOSTE'.
(Other definitions for riposte that I've seen before include "Witty comeback" , "Reply, retort" , "Quick and witty reply" , "Snappy comeback" , "Quick clever reply" .)