hernia vs hiatus

hernia

noun
  • A disorder in which a part of the body protrudes abnormally through a tear or opening in an adjacent part, especially of the abdomen. 

hiatus

noun
  • An opening in an organ. 

  • A gap in a series, making it incomplete. 

  • A gap in geological strata. 

  • A syllable break between two vowels, without an intervening consonant. (Compare diphthong.) 

  • An unexpected break from work. 

  • An interruption, break or pause. 

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