callus vs trauma

callus

noun
  • A hardened area of the skin (especially on the foot or hand) caused by repeated friction, wear or use. 

  • A shining area on the frons of many species of Tabanomorpha (horse flies and relatives). 

  • The material of repair in fractures of bone; a substance exuded at the site of fracture, which is at first soft or cartilaginous in consistency, but is ultimately converted into true bone and unites the fragments into a single piece. 

  • The new formation over the end of a cutting, before it puts out rootlets. 

verb
  • To form such hardened tissue. 

trauma

noun
  • Any serious injury to the body, often resulting from violence or an accident. 

  • An emotional wound leading to psychological injury. 

  • An event that causes great distress. 

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