Final answer:
The question involves understanding the different gaits of standardbred horses, which include trotting and pacing, common terms in English literature when describing horse movements.
Step-by-step explanation:
The question relates to the gait of standardbred horses, which can either be trotters or pacers. This is a concept that might come up in the context of literature where horses and their movements are described, as seen in the given excerpts. For instance, when characters mention horses slowing from a gallop to a canter, then to a trot, they are referring to the different speeds and styles of movement that a horse can perform. Similarly, the mention of racehorses accelerating out of the gate is another reference to the agility and the trained gate of these animals. Eadweard Muybridge's work on Animal Locomotion also showcases the different gaits of horses through sequential photography.