A dromedary is a type of camel. In parts of North Africa, it's popular for riders to race dromedaries.
Another name for the dromedary is the "Arabian camel." Dromedaries are the tallest type of camel, and they always have a single (rather than double) hump on their backs. Despite their height, dromedaries tend to be strong, fast, and light, which is why they have been used for racing. The Late Latin dromedarius means "kind of camel," from a Greek root, dromas kamelos, "running camel."