breathlessness vs respiration

breathlessness

noun
  • The state of being breathless or out of breath. 

  • Difficult or labored respiration, dyspnea, shortness of breath 

respiration

noun
  • An act of breathing; a breath. 

  • Any similar process in an organism that lacks lungs that exchanges gases with its environment. 

  • The process of inhaling and exhaling; breathing, breath. 

  • The process by which cells obtain chemical energy by the consumption of oxygen and the release of carbon dioxide. 

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