favourable vs idoneous

favourable

adj
  • Convenient or at a suitable time; opportune. 

  • Pleasing, encouraging or approving. 

  • Useful or helpful. 

  • Auspicious or lucky. 

noun
  • A favourable person 

idoneous

adj
  • appropriate; suitable 

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