diagnosis vs etiology

diagnosis

noun
  • The identification of the nature and cause of something (of any nature). 

  • A written description of a species or other taxon serving to distinguish that species from all others; especially a description written and published in Latin. 

  • The identification of the nature and cause of an illness. 

verb
  • Synonym of diagnose 

etiology

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