cucumber vs marrow

cucumber

noun
  • The edible fruit of this plant, having a green rind and crisp white flesh. 

  • A vine in the gourd family, Cucumis sativus. 

  • A person who is calm and self-possessed. 

marrow

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

  • 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 friend, pal, buddy, mate. 

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