busk vs strengthen

busk

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

  • To tack, cruise about. 

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

  • A corset. 

strengthen

verb
  • To reinforce, to add to, to support (someone or something) 

  • To make strong or stronger; to add strength to; to increase the strength of; to fortify. 

  • To empower; to give moral strength to; to encourage; to enhearten. 

  • To grow strong or stronger. 

  • To substantiate; to corroborate (a belief, argument, etc.) 

  • To augment; to improve; to intensify. 

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