cold feet vs pusillanimity

cold feet

noun
  • A feeling of nervousness or anxiousness causing one to reconsider a decision about an upcoming event. 

  • Used other than figuratively or idiomatically: see cold, feet. 

pusillanimity

noun
  • The quality or state of being pusillanimous; the vice of being timid and cowardly, and thus not living up to one's full potential; pusillanimousness. 

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