approbative vs unpromising

approbative

adj
  • Sanctioning officially, giving authorization or approval to something. 

  • Expressing approval. 

noun
  • A word or grammatical form which denotes a positive affect expressing the appreciation or approval of the speaker. 

unpromising

adj
  • Not promising 

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