from the GNU version of the Collaborative International Dictionary of English
- n. in deep well boring, an adjusting screw connecting the working beam with the rope carrying the tools, for lowering the tools as the drilling progresses.
- A screw link, to which is attached the rope of a rope-drilling apparatus, for feeding and slightly turning the drill jar at each stroke.
- A set screw used for adjusting.
Sorry, no etymologies found.