outby

Outby is a directional term used primarily in mining to describe locations, passages, or processes that are away from the mine's principal access, typically the shaft or main intake. It is the opposite of inbye, which refers to directions toward the shaft or into the mine. In many British and Irish coal mines, workers and plans use outby/outbye to label crosscuts, roadways, faces, and working sections that lie farther from the shaft than the reference point.

The term can be used as an adverb or an adjective. For example, "the outby face" means the face located away from the shaft; "move outby along the roadway" means travel in the outward direction. Spelling varies by publication: "outbye" is common in some sources, while "outby" is also widely used; both are understood in the mining community, and the choice often reflects local convention.

In practice, the distinction between inbye and outby is important for safety and operations, such as ventilation planning, blasting order, and traffic control, since hazards and procedures can differ by location relative to the shaft. The term is most common in hard rock and coal mining literature; in other contexts, the word is rarely used outside technical or historical discussions of mining.

See also: inbye, mine ventilation, heading, face, roadway, mine plan.