Definition of coaster

The word "coaster" derives from the 18th century term "coaster boat," which referred to a small vessel used to carry goods along the coast. In the mid-19th century, the term "coaster" began to be applied to ceramic or wooden disks that were placed under glasses or cups to prevent water rings from forming on wooden tables. This usage of the word "coaster" migrated to the United States in the late 19th century and became popular as a result of the rise in popularity of Glass Tabletops and the increased use of furniture with wooden tables. Today, the term "coaster" is commonly used to describe small, often decorative mats or placemats placed under glasses or cups to protect surfaces and prevent damage.