mine
n. countablen. a deep hole or tunnel in the ground where people dig for coal, gold, or other valuable rocks. It can also mean a hidden bomb placed under the ground or water.
n. an excavation in the earth for extracting minerals or other geological materials. Also refers to a self-contained explosive device placed on or below the surface of the ground or water, designed to be detonated by the proximity or contact of a person or vehicle.
The workers spend all day underground in the coal mine.
The old gold mine was closed years ago after it became too dangerous for the workers to enter.
Environmental regulations now require companies to restore the landscape after a mine has been exhausted of its natural resources to prevent long-term ecological damage.
Often used with 'for' when describing the material being extracted, such as a 'mine for silver'.