landfall vs sea-coast

landfall and sea-coast both are nouns.

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

As nouns, sea-coast is a hypernym of landfall; that is, sea-coast is a word with a broader meaning than landfall:

Other hypernyms of landfall include coast, seacoast, seashore.

landfall (noun)	sea-coast (noun)
the first sighting of land from the sea after a voyage (or flight over water)	the shore of a sea or ocean
the seacoast first sighted on a voyage (or flight over water)