longing vs need

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 

need

noun
  • A requirement for something; something needed. 

  • Lack of means of subsistence; poverty; indigence; destitution. 

verb
  • To be obliged or required (to do something). 

  • To be required; to be necessary. 

  • To want strongly; to feel that one must have something. 

  • To have an absolute requirement for. 

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