judd
n. countablen. a large piece of coal or rock that is loose and looks like it might fall from the roof of a mine. It is a dangerous situation that miners have to watch out for.
n. a large, unstable mass of coal or rock in a mine roof that is partially detached and at risk of falling. Used primarily in historical or regional British mining contexts.
The miners stopped working when they noticed a heavy judd above them.
Safety inspectors warned the crew about a judd that had formed after the last round of blasting.
In the narrow seams of the northern collieries, the constant threat of a judd required experienced hewers to listen for the subtle creaking of the timber supports.
Primarily a technical term in the coal mining industry; often found in historical accounts of mining accidents.