COUNTERMINE, noun [counter and mine.]

1. In military affairs, a well and gallery sunk in the earth and running under ground, in search of the enemys mine, or till it meets it, to defeat its effect.

2. Means of opposition or counteraction.

3. A stratagem or project to frustrate any contrivance.

COUNTERMINE, verb transitive

1. To sink a well and gallery in the earth, in search of an enemys mine, to frustrate his designs.

2. To counterwork; to frustrate by secret and opposite measures.