promising vs redoubtable

promising

adj
  • Encouraging and inspiring confidence. 

  • Showing promise, and likely to develop in a desirable fashion. 

  • a promising young apprentice 

noun
  • The act of making a promise. 

redoubtable

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

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