combustion vs outbreak

combustion

noun
  • Violent agitation, tumult. 

  • A process wherein a fuel is combined with oxygen, usually at high temperature, releasing heat. 

  • A process whereby two chemicals are combined to produce heat. 

  • The act or process of burning. 

outbreak

noun
  • An outburst or sudden eruption, especially of violence and mischief. 

  • An eruption; the sudden appearance of a rash, disease, etc. 

  • Synonym of breakout (“escape from prison”) 

  • A sudden increase. 

verb
  • To burst out or break forth. 

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