Racing horse (5)
I believe the answer is:
pacer
(Other definitions for pacer that I've seen before include "Competitor" , "setting the rate" , "Racehorse" , "walker?" , "One setting race speed" .)
I believe the answer is:
pacer
(Other definitions for pacer that I've seen before include "Competitor" , "setting the rate" , "Racehorse" , "walker?" , "One setting race speed" .)