noun
: ancient masonry remains apparently of defensive works found especially in Scotland, Ireland, France, and Germany and characterized by siliceous stones converted into a hard glassy material by the action of fire
noun
: ancient masonry remains apparently of defensive works found especially in Scotland, Ireland, France, and Germany and characterized by siliceous stones converted into a hard glassy material by the action of fire
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012