impressive vs promissory

impressive

adj
  • Appealing. 

  • Capable of being impressed. 

  • Making, or tending to make, a positive impression; having power to impress 

promissory

adj
  • Containing or consisting of a promise. 

  • Stipulating the future actions required of the parties to an insurance policy or other business agreement. 

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