a. Mining. [UNDER-1 5 c.] Lying below the level of the bottom of the engine-pit. Also const. of.
1839. Ure, Dict. Arts, 975. What is not included, is termed the under-dip coal. Ibid., 994. Under-dip workings have been already executed more than an English mile under-dip of the engine-pit bottom.
1886. J. Barrowman, Sc. Mining Terms, 69. Under-dip coals.
