impotent vs noneffective

impotent

noun
  • an impotent or powerless person 

  • a man who has erectile dysfunction 

adj
  • lacking physical strength or vigor; weak 

  • incapable of sexual intercourse, often because of an inability to achieve or sustain an erection, having impotentia coeundi 

  • lacking in power, as to act effectively; helpless 

  • sterile 

noneffective

noun
  • A member of the military who is unable to assume active duty. 

adj
  • Not effective. 

  • Not able to assume active duty. 

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