Definition of countermine

• n. - An underground gallery excavated to intercept and destroy the mining of an enemy.
• n. - A stratagem or plot by which another sratagem or project is defeated.
• v. t. - To oppose by means of a countermine; to intercept with a countermine.
• v. t. - To frustrate or counteract by secret measures.
• v. i. - To make a countermine or counterplot; to plot secretly.