redoubtable vs unwavering

redoubtable

adj
  • Eliciting respect or fear; imposing; awe-inspiring. 

unwavering

adj
  • Not doubting or unsure; decisive, firm, resolute. 

  • Always on course and steady. 

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