employ vs undertaking

employ

noun
  • The state of being an employee; employment. 

verb
  • To hire (somebody for work or a job). 

  • To use (somebody for a job, or something for a task). 

  • To make busy. 

undertaking

noun
  • That which is undertaken; any business, work, or project which a person engages in, or attempts to perform; an enterprise. 

  • A promise or pledge; a guarantee. 

  • The business of an undertaker, or the management of funerals. 

  • The act of one who undertakes (in either sense). 

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