CROMLECH
dolmen, cromlech, portal tomb
(noun) a prehistoric megalithic tomb typically having two large upright stones and a capstone
Source: WordNet® 3.1
Etymology
Noun
cromlech (plural cromleches)
A dolmen or ancient underground tomb in Wales, usually made with stones disposed in a circular shape.
Synonym: bowing stone
Source: Wiktionary
Crom"lech (krm"l*k), n. Etym: [W. cromlech; crom bending or bent,
concave + llech a flat stone; akin to Ir. cromleac.] (Arch
Definition: A monument of rough stones composed of one or more large ones
supported in a horizontal position upon others. They are found
chiefly in countris inhabited by the ancient Celts, and are of a
period anterior to the introduction of Christianity into these
countries.
Source: Webster’s Unabridged Dictionary 1913 Edition