Equine gait (4)
I believe the answer is:
trot
'equine gait' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for trot that I've seen before include "A slowish run, often by horse" , "Follower of revolutionary" , "leftie" , "(Horse's) moderate pace" , "Left-winger - move at a fair speed" .)