Emily Dickinson Lexicon

MINE, n. [Fr. mine, a mine or ore, whence mineral; It. mina, miniera; Sp. mina, a mine, a conduit, a subterraneous canal, a spring or source of water; Port. id.; Ir. men, mianach; Dan. and G. mine; Sw. mina; D. myn; W. mwn, whence mwnai, money; Arm. min. The radical signification is not obvious.]

1. A pit or excavation in the earth, from which metallic ores, mineral substances and other fossil bodies are taken by digging. The pits from which stones only are taken, are called quarries.
2. In the military art, a subterraneous canal or passage dug under the wall or rampart of a fortification, where a quantity of powder may be lodged for blowing up the works.
3. A rich source of wealth or other good.