1) Most of the meanings given to this word emphasise its military or negative aspects, literally and figuratively. However, when used in some mining leases it could refer simply to a method of ‘winning’ coals underground.
1666 of their owne Coste … shall sett downe and Sincke one other pitt for under myneinge and gettinge of Cooles, South Crosland. Nevertheless, as mining increased in intensity it was linked with damage done to the ground surface and buildings, and that is evident from the sixteenth century: 1580 yf any person do get cooles … to undermine one hieway called the high Skowte … to forfeite xs, Dewsbury
1683 have digged and undermined the said closes … and those Closes will not in all probability be worth 40s per annum which are now worth the summe of 12li, Whitkirk
1756 We … have view’d the Barn … and are of the opinion that the damages done … are occasioned by getting the Coal and undermining the said Barn, Beeston.