ax to grind vs passion

ax to grind

noun
  • A proposition or point of view to advocate, especially motivated by self-interest. 

  • A grudge or grievance, with implications of confrontation. 

passion

noun
  • A true desire sustained or prolonged. 

  • Fervor, determination. 

  • A display, musical composition, or play meant to commemorate the suffering of Jesus. 

  • The suffering of Jesus leading up to and during his crucifixion. 

  • An object of passionate or romantic love or strong romantic interest. 

  • Any great, strong, powerful emotion, especially romantic love or extreme hate. 

  • Sexual intercourse, especially when very emotional. 

verb
  • To give a passionate character to. 

How often have the words ax to grind and passion occurred in a corpus of books? (source: Google Ngram Viewer )