callous vs gentle

callous

adj
  • Emotionally hardened; unfeeling and indifferent to the suffering/feelings of others. 

  • Having calluses, or relating to calluses. 

gentle

adj
  • Tender and amiable; of a considerate or kindly disposition. 

  • Soft and mild rather than hard or severe. 

  • Polite and respectful rather than rude. 

  • Gradual rather than steep or sudden. 

  • Docile and easily managed. 

noun
  • A trained falcon, or falcon-gentil. 

  • A maggot used as bait by anglers. 

verb
  • To break; to tame; to domesticate. 

  • To soothe; to calm; to make gentle. 

  • To become gentle. 

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