coast vs coastal

coast is a noun but coastal is not a noun.

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

coast (noun)	coastal (noun)
the act of moving smoothly along a surface while remaining in contact with it
the area within view
the shore of a sea or ocean
a slope down which sleds may coast

coast (adjective)	coastal (adjective)
	located on or near or bordering on a coast
	of or relating to a coast
	along or following a coast

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