coaster

(kōˈstər)

1. One that coasts, as:
   a. One who acts in an aimless manner.
   b. A sled or toboggan.
   c. One who rides a sled or toboggan.
2. Nautical A vessel engaged in coastal trade: “dirty British coaster with a salt-caked smokestack” (John Masefield).
3. A roller coaster.
4. a. A small mat or plate placed under a vessel to protect a tabletop or other surface beneath.
   b. A small tray, often on wheels, for passing something, such as a wine decanter, around a table.
5. A resident of a coastal region.