cold feet vs timidity

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. 

timidity

noun
  • The state of being timid; shyness. 

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