Revolutionary way to inject drug (3)
I believe the answer is:
red
'revolutionary' is the definition.
(red can informally mean a communist)
'way to inject drug' is the wordplay.
'way' becomes 'e' (Compass direction - East).
'to inject' is an insertion indicator (inserted letters are injected).
'drug' becomes 'rd' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'e' placed into 'rd' is 'RED'.
Can you help me to learn more?
(Other definitions for red that I've seen before include "Florid" , "- Cross; - carpet" , "- Cross; - admiral" , "eg Cardinal" , "Blushing" .)