In revolutionary movement, discordant about Trotsky's end (8)
I believe the answer is:
gyrating
'in revolutionary movement' is the definition.
(to gyrate can mean to rotate or revolve)
'discordant about trotsky's end' is the wordplay.
'discordant' becomes 'grating' (grating can mean jarring or dissonant).
'about' means one lot of letters goes inside another.
'end' says to take the final letters.
The last letter of 'trotsky' is 'y'.
'grating' enclosing 'y' is 'GYRATING'.
(Other definitions for gyrating that I've seen before include "Whirling" , "Moving with a circular or spiralling motion" , "Circling, spiralling" , "Spinning round" , "Revolving, moving around in circles" .)