outrider vs spy

outrider

noun
  • One who rides out on horseback to inspect a ranch etc. 

  • A guide or escort, especially one who rides in advance. 

  • A forerunner. 

spy

noun
  • A person who secretly watches and examines the actions of other individuals or organizations and gathers information on them (usually to gain an advantage). 

  • A defensive player assigned to cover an offensive backfield player man-to-man when they are expected to engage in a running play, but the offensive player does not run with the ball immediately. 

verb
  • To act as a spy. 

  • To search narrowly; to scrutinize. 

  • To explore; to see; to view; inspect and examine secretly, as a country. 

  • To spot; to catch sight of. 

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