Mine

1. An excavation in the earth from which ore or minerals can be extracted. There was an old mine on the property.
2. The site of such an excavation, with its surface buildings, elevator shafts, and equipment. Coal mines have been the source of many worker deaths.
3. An abundant supply or source of something valuable. That guidebook is a mine of information.
4. An explosive device used to destroy enemy personnel, shipping, fortifications, or equipment, often places in a concealed position and designed to be detonated by contact, proximity, or a time fuse. The harbor was heavily mined to defend the port.
5. Used to indicate that someone or something belongs to me. That book on the table is mine