roofstone (English, noun)
expansion: roofstone (plural roofstones)
Senses:
topics: business
geography
geology
mining
natural-sciences
glosses: The stone or rock layer immediately above a coal seam.
topics: archaeology
history
human-sciences
sciences
glosses: A large, usually flat stone slab placed atop the side-stones (orthostats) of a megalithic burial chamber—such as in portal tombs, wedge tombs, or gallery graves—to form a roof covering the interior space.
Forms:
form: roofstones
tags: plural