Pullman cars are a type of luxurious railway carriage that was once popular in the United States. These cars were originally designed and built by the Pullman Company, which was founded in 1867. While the term "Pullman cars" is still commonly used today to describe this type of carriage, there are many other words that can be used as synonyms for this term. Some of the most common ones include sleeper cars, passenger coaches, parlor cars, and observation cars. Each of these terms refers to a specific type or variation of Pullman carriage, and they are typically used interchangeably depending on the context.