oleiferous vs unctuous

oleiferous

adj
  • That produces oil 

unctuous

adj
  • Oily or greasy. 

  • Rich, lush, intense, with layers of concentrated, soft, velvety flavor. 

  • Profusely polite, especially unpleasantly so and insincerely earnest. 

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