suffossĭo

ōnis, f.

suffodio

I. a digging under, undermining, Vulg. Jer. 51, 58.—Transf., in plur., concr., mines, Vitr. 1, 5, 5 (dub.): cum ipsum solum subfossionibus tremeret, Sen. Ep. 49, 8.
Lewis & Short
A Latin Dictionary, 1879
An open-access project