instrument vs undertake

instrument

verb
  • To devise, conceive, cook up, plan. 

  • To perform upon an instrument; to prepare for an instrument. 

  • To apply measuring devices. 

noun
  • A legal document, such as a contract, deed, trust, mortgage, power, indenture, or will. 

  • A device used to produce music. 

  • A means or agency for achieving an effect. 

  • A tool, implement used for manipulation or measurement. 

  • A person used as a mere tool for achieving a goal. 

  • A measuring or displaying device. 

undertake

verb
  • To take upon oneself; to start, to embark on (a specific task etc.). 

  • To commit oneself (to an obligation, activity etc.). 

  • To pass a slower moving vehicle on the curbside rather than on the side closest to oncoming traffic. 

noun
  • The passing of slower traffic on the curbside rather than on the side closest to oncoming traffic. 

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