undecided vs unflagging

undecided

noun
  • A voter etc. who has not yet come to a decision. 

adj
  • Uncommitted, not having reached a decision. 

  • Open and not yet settled or determined. 

unflagging

adj
  • Never tiring or lacking energy; without rest; without slowing. 

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