rock-ribbed vs unhesitant

rock-ribbed

adj
  • Obstinately firm and unyielding in one's opinions 

  • Having rocky cliffs or outcroppings 

unhesitant

adj
  • Lacking hesitation; not hesitant 

How often have the words rock-ribbed and unhesitant occurred in a corpus of books? (source: Google Ngram Viewer )