standing stone vs megalith

standing stone and megalith both are nouns.

Word	Noun	Adjective	Verb	Adverb
standing stone	Yes	No	No	No
megalith	Yes	No	No	No

As nouns, megalith is a hypernym of standing stone; that is, megalith is a word with a broader meaning than standing stone:

standing stone: a tall upright megalith; found primarily in England and northern France
megalith: memorial consisting of a very large stone forming part of a prehistoric structure (especially in western Europe)

Other hypernyms of standing stone include megalithic structure.

standing stone (noun)	megalith (noun)
a tall upright megalith; found primarily in England and northern France	memorial consisting of a very large stone forming part of a prehistoric structure (especially in western Europe)