katabasis vs retreating

katabasis

noun
  • A retreat, especially a military one. 

  • A journey from the interior of a country to the coast. 

  • Any journey downwards or fall. 

  • The presence of downward (drainage or katabatic) winds. 

  • A mytheme or trope in which the hero embarks on a journey to the underworld. 

retreating

noun
  • The act of moving back from something; a retreat. 

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