Caple is a seldom used word in modern English vocabulary, meaning a horse's pace between a walk and a canter. Although it might not be a commonly used word today, there are still some words that can be used interchangeably with caple to describe the same gait of a horse. Some possible synonyms for caple include jog, trot, or lope. There are also other horse-related words that can be used to describe similar paces, such as canter or gallop. While caple might not be a common word, it's always useful to have a variety of synonyms on hand to add depth and variety to your writing.