day laborer vs navvy

day laborer

noun
  • A laborer who is hired and paid one day at a time, with no promise that more work will be available in the future. 

navvy

noun
  • A laborer on a civil engineering project such as a canal or railroad. 

verb
  • To carry out physical labor on a civil engineering project. 

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