diffidence vs longing

diffidence

noun
  • The state of being diffident, timid or shy; reticence or self-effacement. 

longing

noun
  • An earnest and deep, not greatly passionate, but rather melancholic desire. 

  • The buying of a financial instrument with the expectation that its value will rise 

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