akh vs marrow

akh

noun
  • Brother; a close male friend or associate. 

  • In Egyptian mythology, (roughly) a spirit of the dead that has successfully completed its transition to the afterlife. 

marrow

noun
  • A friend, pal, buddy, mate. 

  • The inner meaning or purpose. 

  • The pith of certain plants. 

  • Bone marrow biopsy. 

  • The essence; the best part. 

  • The substance inside bones which produces blood cells. 

  • A kind of vegetable like a large courgette/zucchini or squash. 

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