harm vs undermine

harm

verb
  • To cause injury to another; to hurt; to cause damage to something. 

noun
  • detriment; misfortune. 

  • physical injury; hurt; damage 

  • That which causes injury, damage, or loss. 

  • emotional or figurative hurt 

undermine

verb
  • To weaken or work against; to hinder, sabotage. 

  • To erode the base or foundation of something, e.g. by the action of water. 

  • To dig underneath (something), to make a passage for destructive or military purposes; to sap. 

How often have the words harm and undermine occurred in a corpus of books? (source: Google Ngram Viewer )