doubt vs vim

doubt

verb

  • To be undecided about; to lack confidence in; to disbelieve, to question. 

noun

  • Disbelief or uncertainty (about something); (countable) a particular instance of such disbelief or uncertainty. 

vim

noun

  • Ready vitality and vigour. 

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