shore vs sea-coast

shore and sea-coast both are nouns.

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

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

Other hyponyms of shore include lakeshore, lakeside, coast, seacoast, seashore, strand.

shore (noun)	sea-coast (noun)
a beam or timber that is propped against a structure to provide support	the shore of a sea or ocean
the land along the edge of a body of water

shore (verb)	sea-coast (verb)
support by placing against something solid or rigid
arrive on shore
serve as a shore to