Mine pig

Mine Mine, n. [F., fr. LL. mina. See {Mine}, v. i.] [1913 Webster] 1. A subterranean cavity or passage; especially: (a) A pit or excavation in the earth, from which metallic ores, precious stones, coal, or other mineral substances are taken by digging; -- distinguished from the pits from which stones for architectural purposes are taken, and which are called quarries. (b) (Mil.) A cavity or tunnel made under a fortification or other work, for the purpose of blowing up the superstructure with some explosive agent. [1913 Webster]

2. Any place where ore, metals, or precious stones are got by digging or washing the soil; as, a placer mine. [1913 Webster]

3. (Fig.): A rich source of wealth or other good. --Shak. [1913 Webster]

4. (Mil.) An explosive device placed concealed in a location, on land or at sea, where an enemy vehicle or enemy personnel may pass through, having a triggering mechanism which detects people or vehicles, and which will explode and kill or maim personnel or destroy or damage vehicles. A mine placed at sea (formerly called a {torpedo}, see {torpedo}[2] (a) ) is also called an marine mine and underwater mine and sometimes called a floating mine, even though it may be anchored to the floor of the sea and not actually float freely. A mine placed on land (formerly called a {torpedo}, see {torpedo}[3]), usually buried, is called a land mine. [PJC]

{Mine dial}, a form of magnetic compass used by miners.

{Mine pig}, pig iron made wholly from ore; in distinction from {cinder pig}, which is made from ore mixed with forge or mill cinder.

{gold mine} (a) a mine where gold is obtained. (b) (Fig.) a rich source of wealth or other good; same as {Mine} 3. --Raymond. [1913 Webster]