abstractive vs doubtful

abstractive

adj
  • Having an abstracting nature or tendency; tending to separate; tending to be withdrawn. 

  • Derived by abstraction; belonging to abstraction. 

doubtful

adj
  • Subject to, or causing doubt. 

  • Experiencing or showing doubt, sceptical. 

  • Improbable or unlikely. 

  • Unclear or unreliable. 

  • Suspicious, or of dubious character. 

  • Undecided or of uncertain outcome. 

noun
  • A doubtful person or thing. 

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