A local name for a JOINT in the bedding of slate or other rock.
1662. Ray, Itin., III. in Lankester, Mem. John Ray (1846), 185. At Denbyboul, about two miles from Tintagel, is the best quarry of slate in the country…. It is divided … both longways and broadways, by cracks or rifts, which they call junks.
