Answer: undermines

AnswerCrossword Clue
underminesUNDERMINE, to dig beneath (eg a wall) in order to make it fall also UNDERMINDE
underminesDamage or weaken (someone or something), esp. gradually or insidiously
underminesErode the base or foundation of (a rock formation)
underminesDig or excavate beneath (a building or fortification) so as to make it collapse