employ vs vacancy

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. 

vacancy

noun
  • An unoccupied position or job. 

  • Empty space. 

  • An available room in a hotel; guest house, etc. 

  • Lack of intelligence or understanding. 

  • A blank mind, unoccupied with thought. 

  • A defect in a crystal caused by the absence of an atom in a lattice 

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