shore vs bolster

shore and bolster both are nouns.

Word	Noun	Adjective	Verb	Adverb
shore	Yes	No	Yes	No
bolster	Yes	No	Yes	No

As verbs, bolster is a hyponym of shore; that is, bolster is a word with a more specific, narrower meaning than shore:

shore (noun)	bolster (noun)
a beam or timber that is propped against a structure to provide support	a pillow that is often put across a bed underneath the regular pillows
the land along the edge of a body of water

shore (verb)	bolster (verb)
support by placing against something solid or rigid	add padding to
arrive on shore	support and strengthen
serve as a shore to	prop up with a pillow or bolster