assailant vs white knight

assailant

noun
  • Someone who attacks or assails another violently, or criminally. 

  • A hostile critic or opponent. 

adj
  • Assailing; attacking. 

white knight

noun
  • Someone who unnecessarily defends someone else. 

  • An individual or corporation that intends to acquire another company in order to avert a hostile takeover. 

  • A man who defends a woman in debate etc. in an attempt to gain her favour. 

  • A mushroom of species Tricholoma album. 

  • A hero, savior, or righteous individual. 

verb
  • To unnecessarily defend someone, especially in an attempt to gain favour. 

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