tentative vs vicarial

tentative

adj
  • restrained; polite; feeling one's way, not using full force. 

  • Uncertain; subject to future change. 

  • Of or pertaining to a trial or trials; essaying; experimental. 

noun
  • A trial; an experiment; an attempt. 

vicarial

adj
  • Delegated; vicarious 

  • Of or pertaining to a vicar 

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