chronic vs hardened

chronic

adj
  • Inveterate or habitual. 

  • Good, great; "wicked". 

  • Of a problem, that continues over an extended period of time. 

  • Very bad, awful. 

  • Prolonged or slow to heal. 

  • Of a person, suffering from an affliction that is prolonged or slow to heal. 

  • Extremely serious. 

noun
  • A condition of extended duration, either continuous or marked by frequent recurrence. Sometimes implies a condition which worsens with each recurrence, though that is not inherent in the term. 

  • Marijuana, typically of high quality. 

  • A person who is chronic, such as a criminal reoffender or a person with chronic disease. 

hardened

adj
  • Firmly established or unlikely to change; inveterate. 

  • Inured; toughened. 

  • Having extra defences against attack; highly fortified. 

  • Unfeeling; pitiless; callous. 

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