piece work vs wage

piece work

noun
  • Work that a worker is paid for according to the number of units produced, rather than the number of hours worked; work done and paid for by the piece or by the job. 

wage

noun
  • An amount of money paid to a worker for a specified quantity of work, usually calculated on an hourly basis and expressed in an amount of money per hour. 

verb
  • To conduct or carry out (a war or other contest). 

  • To adventure, or lay out, for hire or reward; to hire out. 

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