Inflamed by a revolutionary? (3)
I believe the answer is:
red
I believe this clue is a double definition.
'inflamed' is the first definition.
(synonyms)
'a revolutionary?' is the second definition.
(red can informally mean a communist)
'by' is the link.
(Other definitions for red that I've seen before include "Ruby" , "Colour of blood" , "- Cross; - admiral" , "Crimson" , "Colour of Merlot wine" .)