coaster (n.) Look up coaster at Dictionary.com
1570s, "one who sails along coasts," agent noun from coast (v.) in its original sense "to go around the sides or border" of something. Applied to vessels for such sailing from 1680s. Tabletop drink stand (c.1887), originally "round tray for a decanter," so called from a resemblance to a sled, or because it "coasted" around the perimeter of the table to each guest in turn after dinner.