Opencast

Part of speech: adjective

Definitions

1. Pertaining to a method of mining where materials are extracted from an open pit on the surface instead of underground
2. Describing a mining technique involving the removal of minerals from large surface excavations rather than tunnels
3. Concerning the process of extracting resources by digging them out from an uncovered excavation on the earth's surface

Etymology: "Opencast" is a plain compound of "open" and "cast," and its history is mostly about the second element. "Cast" here is the mining sense of the word: to throw or fling, which in its older mining use meant to dig out or excavate material. An opencast mine, then, is one worked by digging from the surface rather than by sinking shafts or tunnels underground, and the adjective describes that method. The "open" part is the ordinary English word for a site without a roof or enclosure, so the compound describes exactly what it says: a working that is exposed to the sky. The term is most often used of coal and other ores, where the distinction between surface and underground extraction matters both technically and economically.

Synonyms: open-pit, surface, strip-mined, quarry, excavated