coast vs coaster

coast and coaster both are nouns.

Word	Noun	Adjective	Verb	Adverb
coast	Yes	No	Yes	No
coaster	Yes	No	No	No

coast (noun)	coaster (noun)
the act of moving smoothly along a surface while remaining in contact with it	a covering (plate or mat) that protects the surface of a table (i.e., from the condensation on a cold glass or bottle)
the area within view	someone who coasts
the shore of a sea or ocean	a resident of a coastal area
a slope down which sleds may coast

coast (verb)	coaster (verb)
move effortlessly; by force of gravity