false friend vs traitor

false friend

noun
  • Used other than figuratively or idiomatically: see false, friend. 

  • A word in a language that bears a deceptive resemblance to a word in another language but in fact has a different meaning. 

traitor

noun
  • One who betrays any confidence or trust. 

  • Someone who violates an allegiance and betrays their country; someone guilty of treason; one who, in breach of trust, delivers their country to an enemy, or yields up any fort or place entrusted to their defense, or surrenders an army or body of troops to the enemy, unless when vanquished. 

  • Someone who takes arms and levies war against their country; or one who aids an enemy in conquering their country. 

verb
  • To act the traitor toward; to betray; to deceive. 

adj
  • Traitorous. 

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