Communist holding out though badly beaten (6)
I believe the answer is:
routed
'badly beaten' is the definition.
'routed' can be an answer for 'beaten' (synonyms). I am not certain of the 'badly' bit.
'communist holding out' is the wordplay.
'communist' becomes 'red' (red can informally mean communist).
'holding' means one lot of letters goes inside another.
'red' enclosing 'out' is 'ROUTED'.
'though' acts as a link.
Can you help me to learn more?
(Other definitions for routed that I've seen before include "Decisively defeated" , "Put to flight or sent a certain way" , "Sent packing" , "getting beaten" , "Sent in particular direction by way of detour" .)