Coaster (noun)

1. A small mat or tray on which a glass or cup is placed to protect the surface of a table or counter.
2. A small vehicle, typically on rails, used for amusement park rides, often designed to simulate the experience of riding on a roller coaster.
3. A ship used for trade or transport, particularly one that travels along the coast.
4. A person or thing that moves rapidly, or is used to transport something quickly.

Origin:

From the middle english word 'costere', meaning a cup or mug, which comes from the old french word 'costier', meaning to stand by. the sense of a tray or mat used to protect a surface from a cup or glass dates to the 1880s.

Examples:

1. The waitress placed a coaster under my glass of water.
2. The kids begged their parents to let them ride the roller coaster.
3. The coaster sailed along the coast, carrying its precious cargo of spices.
4. He used a coaster to transport the hot pizza from the oven to the table.
5. The company ordered a fleet of coasters to deliver their products to customers along the coast.