activity vs lassitude

activity

noun
  • The lexical aspect (aktionsart) of verbs or predicates that change over time and have no natural end point. 

  • Something done as an action or a movement. 

  • Something done for pleasure or entertainment, especially one involving movement or an excursion. 

  • The state or quality of being active; activeness. 

  • The number of radioactive decays per unit time. Unit for it: becquerel or curie 

  • The propery of substances to react with other substances 

lassitude

noun
  • Lethargy or lack of energy; fatigue. 

  • Listlessness or languor. 

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