Republican receiving one hard hit (7)
I believe the answer is:
triumph
'hit' is the definition.
(I've seen this before)
'republican receiving one hard' is the wordplay.
'republican' becomes 'trump' (I can't justify this - if you can you should give a lot more credence to this answer).
'receiving' is an insertion indicator.
'one' becomes 'i' (Roman numeral).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'trump' enclosing 'i' is 'triump'.
'triump'+'h'='TRIUMPH'
Can you help me to learn more?
(Other definitions for triumph that I've seen before include "Successful ending of a struggle or contest" , "Victory - jubilation" , "beat the opposition!" , "Victory, great success" , "Prove superior" .)