trilithon
noun
tri·lithon
(ˈ)trī¦liˌthän,
ˈtrīləˌth-
variants or less commonly trilith
ˈtrīˌlith
plural -s
: an ancient stone monument consisting of two upright megaliths carrying a third as a lintel
Word History
Etymology
New Latin trilithon, from Greek, neuter of trilithos of three stones, from tri- three + lithos stone