irresolute vs tentative

irresolute

adj
  • Undecided or unsure how to act. 

  • Indecisive or lacking in resolution. 

tentative

adj
  • Uncertain; subject to future change. 

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

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

noun
  • A trial; an experiment; an attempt. 

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