alleviation vs alterative

alleviation

noun
  • the act of reducing pain or anything else unpleasant; easement 

  • the act of alleviating; relief or mitigation. 

alterative

noun
  • A medicine or treatment which works by changing processes within the body, rather than by evacuating something etc. 

adj
  • Gradually changing, or tending to change, a morbid state into a healthy one. 

  • Causing alteration. 

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