Run in strict rotation (4)
I believe the answer is:
trot
'run' is the definition.
(I know that run is a is a kind of of trot)
'in strict rotation' is the wordplay.
'in' indicates a hidden word.
'TROT' is hidden within 'strict rotation'.
(Other definitions for trot that I've seen before include "Left-winger - move at a fair speed" , "(Horse's) pace faster than a walk" , "Brisk movement" , "Run at moderate pace" , "Moderate running pace" .)