disease vs unsadness

disease

noun
  • Lack of ease; uneasiness; trouble; vexation; disquiet. 

  • Any abnormal or harmful condition, as of society, people's attitudes, way of living etc. 

  • An abnormal condition of a human, animal or plant that causes discomfort or dysfunction; distinct from injury insofar as the latter is usually instantaneously acquired. 

verb
  • To infect with a disease. 

unsadness

noun
  • infirmity, unsteadiness, weakness 

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