Horse

From WikiPOBia

Sometimes called the foot-rope, the horse is a line, pendant from a boom or yard, on which the men working or traversing that yard stand. Because the bowsprit and jibbooms generally had a small slope to them, knots were often tied in the horses to prevent the feet of the men standing on them from sliding backwards. If the horse were only fixed at its extremities, the weight of the men working on it would pull the horse down into a deep V-shape, putting the man at the bottom at a dangerous height and creating treacherous slopes for the others. To resolve this problem, horses of any length are passed through eye splices in short lines called stirrups which were then made fast to the yard above or to the yard's jack stay.

Flemish Horse

While the horses on smaller yards extend from the slings to the yardarms, longer yards generally included a Flemish horse, i.e., a horse extending from the yardarm to, perhaps, four yards in, on which the outermost men would stand.