blockage vs catalyst

blockage

noun
  • Synonym of constipation (“impairment of feces passage”). 

  • The thing that is the cause of such a state, blocking a passage. 

  • The state or condition of being blocked. 

  • Synonym of thrombosis, synonym of thromboembolism, or synonym of embolism. 

catalyst

noun
  • A substance that increases the rate of a chemical reaction without being consumed in the process. 

  • A catalytic converter. 

  • An object that facilitates the casting of a spell (such as a magic wand). 

  • Something that encourages progress or change. 

  • An inciting incident that sets the successive conflict into motion. 

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