A glossary of some slate industry terms
| Adit | The entrance to a tunnel |
| Back filling | Using waste rock to fill underground workings |
| Bad rock | Unproductive rock found during working |
| Balanced incline | Incline with 2 tracks where the descent of the loaded wagons drew up empty wagons |
| Barracks | Accomodation block used by quarrymen during the week |
| Black powder | A primitive form of explosive |
| Block | Large piece of quarried slate |
| Blondin | A wire rope across a pit with a carriage for wagons to attach to, enabling them to be raised and lowered |
| Chain incline | Suspended incline using a wire rope instead of rails and an inclined plane |
| Chamber | The underground working area - up to 70 foot wide |
| Chwarel | Welsh name for a quarry |
| Cowjian | Plug chisel used for block splitting |
| Crimp | The top edge of an incline |
| Cupboarding | Dangerous practice of cutting into roofing pillars to get cheap slate |
| Cyffell | Long wide knife used to trim roofing slates to size |
| Drum | Horizontal drum around which the ropes of a balanced incline were wound |
| Firesetting | Old practice of loosening slate by using fire |
| Flat rods | Horizontal hinged wooden rods used to convey the power of a water wheel over a distance |
| Floor | working level of a quarry, usually numbered or lettered |
| Hunter | Large circular saw with replaceable teeth |
| Jwmpah | Long weighted rod used to manually bore a hole |
| Launder | Trough for carrying water |
| Llechi | General term for slate |
| Mill | building where slate is reduced using machinery |
| Pelton Wheel | Advanced form of water wheel |
| Pillar | Column of slate left underground to support the area above it |
| Pillar robbing | Thinning of the pillars to get "free" slate (see also cupboarding) |
| Pillaring line | A line of weakness in rock allowing blocks to be removed |
| Planer | Machine used to smooth the surface of a slab |
| Powder house | Purpose built building used to store explosives |
| Pric Mesur | Serrated stick with a nail in the end used to mark out roofing slate sizes |
| Rhys | Large mallet used to break slate blocks |
| Rubbish | Waste rock from the quarrying process |
| Sinc | A pit working |
| Slideway | An unrailed incline where the rock was pushed down |
| Strike | A tunnel bored horizontally into the slate vein |
| Terrace | Working level of an open quarry, usually numbered or lettered |
| Trimmer | Machine used to trim roofing slates to size |
| Twll | A pit working |
| Untopping | Removing the earth and rock from above underground workings to remove the pillars |
| Waliau | Open fronted sheds where slate was hand trimmed and dressed |
| Water balance | Type of incline where the weight of water is used to raise wagons |
| Winding House | Structure where the drum of an incline is housed |
