Definition of coaster
1
: one that coasts: such as
a
: a person engaged in coastal traffic or commerce
b
: a ship sailing along a coast or engaged in trade between ports of the same country
2
: a resident of a seacoast
3 a
: a tray or decanter stand usually of silver and sometimes on wheels
b
: a shallow container or a plate or mat to protect a surface
4 a
: a small vehicle (such as a sled or wagon) used in coasting
b
: roller coaster
