Also 8–9 lum.
1. Mining. † a. A well for the collection of water in a mine. Obs.
1747. Hooson, Miner’s Dict., M iij. When Shafts are sunk down and troubled with Water, we Sink two or three Yards deeper than the Design of the Shaft, on purpose to hold Water one Night at least,… and this we call a Lumb.
b. (See quot. 1883.)
1747. Hooson, Miner’s Dict., s.v. Break-off, An Alteration in a Vein, made by a jumbled Place, or Lumb of Softness.
1883. Gresley, Gloss. Coal-mining, Lum [in Derbyshire], a basin or natural swamp in a coal seam, often running several hundred yards in length.
2. ‘A deep pool in the bed of a river’ (E. D. D.).
1790. Grose, Prov. Gloss., Lum, a deep pool.
