busk vs mainstay

busk

noun
  • A strip of metal, whalebone, wood, or other material, worn in the front of a corset to stiffen it. 

  • A corset. 

verb
  • To solicit money by entertaining the public in the street or in public transport. 

  • To tack, cruise about. 

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. 

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