endowment vs impotence

endowment

noun
  • Property or funds invested for the support and benefit of a person or not-for-profit institution. 

  • Something with which a person or thing is endowed. 

  • Endowment assurance or pure endowment. 

  • A ceremony designed to prepare participants for their role in the afterlife. 

impotence

noun
  • Inability to copulate or beget children; sterility, erectile dysfunction, etc. 

  • Powerlessness; incapacity. 

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