I. ˈ ̷ ̷ ̷ ̷+ˌ- noun
Etymology: counter- + mine (subterranean passage)
1. : a tunnel for intercepting an enemy mine
2. : a stratagem for defeating an attack : counterplot
II. | ̷ ̷ ̷ ̷+ transitive verb
1. : to frustrate or combat by secret measures
know exactly the play of another in order to countermine him — Henry Fielding
2. : to oppose by means of a countermine : intercept with a countermine : destroy (a laid mine or a minefield) with an explosion
intransitive verb
: to make or lay down countermines