A spur is a metal tool designed to be worn in pairs on the heels of riding boots for the purpose of directing a horse to move forward or laterally while riding. It is usually used to refine the riding aids (commands) and to back up the natural aids (the leg, seat, hands and voice). The spur is used in every equestrian discipline.
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spur A kind of small sharp bony or horny spike pointing rearward, near the foot of certain male galliform birds.