coast vs landfall

coast and landfall both are nouns.

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

As nouns, landfall is a hyponym of coast; that is, landfall is a word with a more specific, narrower meaning than coast:

Other hyponyms of coast include litoral, littoral, littoral zone, sands, seaboard, seaside, tideland.

coast (noun)	landfall (noun)
the act of moving smoothly along a surface while remaining in contact with it	the first sighting of land from the sea after a voyage (or flight over water)
the area within view	the seacoast first sighted on a voyage (or flight over water)
the shore of a sea or ocean
a slope down which sleds may coast

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