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sub-terrānĕus, a, um, adj. [terra], underground, subterranean (class.): specus, Cic. Att. 15, 26, 4; cf.: supterraneos specus aperire, Tac. G. 16: ergastulum, Col. 1, 6, 3: structura, Plin. 36, 22, 50, § 170: regna, Juv. 2, 149: animalia, Pall. Sept. 3, 2: mures, Sen. Q. N. 3, 16, 3: subterraneis venis in mare defluunt, Plin. 9, 15, 20, § 53: domus, id. 36, 13, 19, § 88: cubiculum, Plin. Ep. 4, 11, 9: subterraneis dolis peractum urbis excidium, Flor. 1, 12 fin.
Subst.: sub-terrānĕum, i, n., a subterranean place: in ipso subterraneo semirotundo, App. M. 11, p. 260, 2.