Undermine

Verb

 * 1) hinder, sabotage
 * The war efforts were undermined by the constant bickering between the allies.
 * 1) To dig, tunnel, hollow out as if making a cave or opening.

Antonyms

 * undergird

Thesaurus
abate, answer, answer conclusively, argue down, attenuate, blunt, bugger up, confound, confute, contradict, controvert, cramp, cripple, crush, damage, damp, dampen, dash, deaden, debilitate, defeat, demolish, deny, devitalize, disable, dismiss, dispose of, drain, dull, enervate, enfeeble, eviscerate, exhaust, extenuate, finish, floor, foil, frustrate, gruel, harm, honeycomb, hurt, impair, lay low, mine, mitigate, nonplus, overset, overthrow, overturn, overwhelm, parry, put to silence, queer, rattle, rebut, reduce, reduce to silence, refute, ruin, sabotage, sap, sap the foundations, settle, shake, shake up, shut up, silence, smash all opposition, soften up, spoil, squash, squelch, subvert, threaten, throw down, throw over, thwart, unbrace, undercut, unman, unnerve, unstrengthen, unstring, upend, upset, weaken, wreck