corvee vs effort

corvee

noun
  • Unpaid labor required by a feudal lord. 

  • Labor, especially for roads or dams, in lieu of taxes. 

effort

noun
  • An endeavor. 

  • The work involved in performing an activity; exertion. 

  • A force acting on a body in the direction of its motion. 

verb
  • To make an effort. 

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