Why did they call the roller coaster a coaster?

Roller coasters are not named after coasters. The term "coaster" in this context refers to the small sleds or cars that carry passengers along the tracks of a roller coaster. The origin of the term "coaster" in this sense is uncertain, but it is believed to have come from the verb "to coast," meaning to move along smoothly and effortlessly. This meaning of "coast" is derived from the Dutch word "koetsen," which means "to skate" or "to slide."