Noun
a mine where coal is dug from the ground
Source: WordNetDidn't they know that the only unhackable computer is one that's running a secure operating system, welded inside a steel safe, buried under a ton of concrete at the bottom of a coal mine guarded by the SAS and a couple of armoured divisions, and switched off? Charles Stross
After all, game shows are not like working in a coal mine. Drew Carey
I sometimes wondered what the use of any of the arts was. The best thing I could come up with was what I call the canary in the coal mine theory of the arts. Kurt Vonnegut
The average life expectancy of a celebrity is 20 years less than someone working in a coal mine. Moby
Here in Indiana and in many states throughout the union, we rely on coal to power our homes and provide good-paying middle class jobs - like the one my family relied on when I was a kid. The coal mine helped put food on our table and helped me pursue an education and realize the American Dream. Larry Bucshon
I don't have any great first job tales: I've never worked on a tramp steamer or in a coal mine or anything like that. I think the inspiration for my writing came largely from my father and the joy that life in books represented to me. Mary Gordon