forwrought vs impervious

forwrought

adj
  • Blocked; obstructed. 

  • Worked-up; agitated; troubled. 

impervious

adj
  • Preventive of any penetration; impenetrable, impermeable, particularly of water. 

  • Unaffected or unable to be affected by something. 

  • Immune to damage or effect. 

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