activity vs lull

activity

noun
  • The state or quality of being active; activeness. 

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

  • The propery of substances to react with other substances 

lull

noun
  • A period of reduced activity; a respite 

  • A period of rest or soothing. 

  • A period without waves or wind. 

  • An extended pause between sets of waves. 

verb
  • To cause to rest by soothing influences; to compose; to calm 

  • To become gradually calm; to subside; to cease or abate. 

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