[UNDER-2.] (See quots.)
1852. Eng. & Foreign Mining Terms (1860), 66. Underlevel drift, a drift driven from the pumping-pit to un-water dip workings.
1883. Gresley, Gloss. Coal-m., 267. Under-level, winning the ironstone by driving drifts into the hill-sides, &c., instead of sinking shafts.
