Of or pertaining to mines

Extraction of minerals from under the land or sea for industrial or domestic uses. Exhaustion of traditionally accessible resources has led to development of new mining techniques; for example, extraction of oil from offshore deposits and from land shale reserves. Technology is also under development for the exploitation of minerals from entirely new sources such as mud deposits and mineral nodules from the sea bed.
Mud deposits are laid down by hot springs (about 350şC/660şF): sea water penetrates beneath the ocean floor and carries copper, silver, and zinc with it on its return. Such springs occur along the midocean ridges of the Atlantic and Pacific and in the geological rift between Africa and Arabia under the Red Sea.
Mineral nodules form on the ocean bed and contain manganese, cobalt, copper, molybdenum, and nickel; they stand out on the surface, and “grow” by only a few millimeters every 100,000 years.
The deepest mine in Europe is a 1100 m deep working salt and potash mine at Boulby near Whitby on the northeast coast of England.
The act of extracting ores or coal etc from the earth; SYN. excavation.

In warfare, military term meaning to drive a tunnel beneath an enemy position. The end of the tunnel is filled with explosives which are then detonated so as to destroy the position and its occupants.
The technique was frequently employed on the Western Front during World War I, but its drawback was that the enormous crater created could often be defended by unharmed troops quicker than the attackers could reach it.
Laying explosive mines in concealed places to destroy enemy personnel and equipment; SYN. minelaying.