competent vs inefficacious

competent

adj
  • Resistant to deformation or flow. 

  • Having sufficient skill, knowledge, ability, or qualifications. 

  • Having jurisdiction or authority over a particular issue or question. 

  • Adequate for the purpose. 

  • Permeable to foreign DNA. 

inefficacious

adj
  • Incapable of having the intended consequence. 

  • Not effective. 

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