(2) (a) an underground mine passageway driven at right angles to the main entry to connect it with a parallel entry of air course, (b) a horizontal opening driven across the course of a vein or in general perpendicular to the direction of the main workings.
A crosscut is a cut across the grain of a workpiece and may be referred to as a miter, bevel, compound (miter and bevel simultaneously), or straight crosscut. These cuts are commonly made with portable and bench top/stationary circular saws.
A passageway driven between the entry and its parallel air course or air courses for ventilation purposes. Also, a tunnel driven from one seam to another through or across the intervening measures; sometimes called "crosscut tunnel", or "breakthrough". In vein mining, an entry perpendicular to the vein.