See undermine in Webster's New World Roget's A-Z Thesaurus II
verb
To lessen or deplete the nerve, energy, or strength of:
attenuate, debilitate, devitalize, enervate, enfeeble, sap2, undo, unnerve, weaken. See strongTo damage, destroy, or defeat by sabotage:
sabotage, subvert. See attack
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