mainstay vs mastrope

mainstay

noun
  • A stabilising rope from the top of the mainmast to the bottom of the foremast. 

  • Someone or something that can be depended on to make a regular contribution. 

  • A chief support. 

mastrope

noun
  • A rope used in supporting a mast; a stay. 

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