A red wound ultimately throbbed (5)
I believe the answer is:
ached
'throbbed' is the definition.
(I've seen this before)
'a red wound ultimately' is the wordplay.
'red' becomes 'Che' (as in Che Guevara, a communist or 'red').
'ultimately' indicates one should take the final letters.
The final letter of 'wound' is 'd'.
'a'+'che'+'d'='ACHED'
(Other definitions for ached that I've seen before include "Felt a dull pain" , "Did long" , "Throbbed" , "Yearned" , "Hurt" .)