from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A prehistoric structure consisting of two large stones set upright to support a third on their tops, found especially in Europe.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A structure consisting of two stone pillars supporting a horizontal stone
from the GNU version of the Collaborative International Dictionary of English
- n. A monument consisting of three stones; especially, such a monument forming a kind of doorway, as among the ancient Celts.
from The Century Dictionary and Cyclopedia
- n. Same as trilith.
Greek, neuter of trilithos, having three stones : tri-, tri- + lithos, stone.(American Heritage® Dictionary of the English Language, Fourth Edition)