subterius

subtĕrĭor, us, comp. [subter], that is farther beneath, lower, = inferior (late Lat.): termini, Innoc. Cas. Lit. p. 232 Goes.:

per subteriora,

Aem. Mac. 2, 13.—Hence, adv.: subtĕrĭus, lower, farther down:

subterius nigro, superius mineo,

Isid. Orig. 16, 8, 4.