Revolutionary, but without much dash? (4)
I believe the answer is:
trot
'revolutionary' is the definition.
(abbreviation of Trotskyite)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for trot that I've seen before include "Communist - horse pace faster that a walk" , "moderate movement" , "equestrians sometimes associate with rising" , "Militant socialist (informal)" , "Red" .)