countermine noun & verb. 
['kaʊntǝmʌɪn] LME.[from COUNTER- 2 + MINE noun.]A. noun.
1.  Military. A subterranean excavation made by defenders to intercept one made by besiegers. 
LME.2.  fig. A counterplot. 
L16.b. verb.
1.  verb trans. & intrans. Make a countermine (against). 
L16.2.  verb trans. Defeat by a counterplot. 
L16.3.  verb intrans. Lay mines intended to explode an enemy's mines. 
L19. ■   counterminer noun L17.  [TahlilGaran] English Dictionary ▲