mud-kicker vs racehorse

mud-kicker

noun
  • A racehorse. 

  • Streetwalker; a prostitute who looks for customers in public places, especially one who works for a pimp. 

  • An unskilled laborer; One who makes his living by outdoor manual labor. 

  • A workboot designed for outdoor work, especially one that can be worn on muddy ground. 

racehorse

noun
  • A horse that competes in races. 

How often have the words mud-kicker and racehorse occurred in a corpus of books? (source: Google Ngram Viewer )