trilithon

trilithon (trai-LITH-on, TRAI-luh-thon) - n., an ancient structure consisting of two upright megaliths carrying a third as a lintel.



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Such as the above one at Stonehenge. While a few dolmens have only two uprights, those are generally smaller than the crosspiece, while the classic trilithon has a distinctly smaller lintel. Coined by English antiquary William Stukeley from Ancient Greek, neuter of trilithos, having three stones, from tri-, three + lithos, stone.

(The last three days weren't a theme week because I wasn't finding two more related words I wanted to run. So a sort of undeclared mini-theme.)

---L.