A person who, more often in the past, rode on one of a team of horses that were pulling a coach: The postilion usually rode on one of the two or more steeds that were drawing a carriage in order to guide them; especially, when the four-wheeled coach didn't have a coachman.

One day, Brenda and Cindy saw the postilion in his colorful uniform with brass buttons as he was riding one of the mounts and guiding all of the equines (horses) that were hauling the coach.