cromlech vs dolmen

cromlech and dolmen both are nouns.

Word	Noun	Adjective	Verb	Adverb
cromlech	Yes	No	No	No
dolmen	Yes	No	No	No

As nouns, cromlech and dolmen are synonyms defined as:

cromlech and dolmen: a prehistoric megalithic tomb typically having two large upright stones and a capstone

Other synonyms of cromlech include portal tomb.

cromlech (noun)	dolmen (noun)
a prehistoric megalithic tomb typically having two large upright stones and a capstone	a prehistoric megalithic tomb typically having two large upright stones and a capstone