excitation vs unhappiness

excitation

noun
  • The activity produced in an organ, tissue, or part, such as a nerve cell, as a result of stimulation 

  • The act of exciting or putting in motion; the act of rousing up or awakening. 

  • The act of producing excitement (stimulation); also, the excitement produced. 

  • A transition of a nucleus, atom or molecule to an excited state by the absorption of a quantum of energy; the opposite of relaxation 

unhappiness

noun
  • The feeling of not being happy 

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