coast‧er /ˈkəʊstə $ ˈkoʊstər/ noun [countable]

1. a small thin object on which you put a glass, or cup, to protect a table from heat or liquids

2. a ship that sails from port to port along a coast, but does not go further out to sea
⇒ roller coaster

[TahlilGaran] Dictionary of Contemporary English ▲