unoriginal vs workhorse

unoriginal

noun
  • A person or work that does not exhibit originality. 

adj
  • Not being the first or earliest version of something, not original. 

  • Lacking originality. 

workhorse

noun
  • Anyone or anything that does a lot of work; something or someone who works consistently or regularly. 

  • A horse used primarily for manual labor; a draft horse. 

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