obstruction vs quelling

obstruction

noun
  • The act of obstructing, or state of being obstructed. 

  • Something which obstructs or impedes, either intentionally or unintentionally 

  • The condition of having the natural powers obstructed in their usual course; the arrest of the vital functions; death. 

quelling

noun
  • The act by which something is quelled. 

adj
  • causing something to quell or be quelled 

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