sleeper vs spy

sleeper

noun
  • A spy, saboteur, or terrorist who lives unobtrusively in a community until activated by a prearranged signal; may be part of a sleeper cell. 

  • A railroad tie. 

  • A goby-like bottom-feeding freshwater fish of the family Odontobutidae. 

  • A type of pajama for a person, especially a child, that covers the whole body, including the feet. 

  • A sleeper hold. 

  • A heavy floor timber in a ship's bottom. 

  • A nurse shark (family Ginglymostomatidae). 

  • That which lies dormant, as a law. 

  • A sedative. 

  • A bet placed on the gambling table and then forgotten about by the gambler. 

  • An automobile which has been internally modified to excess, while retaining a mostly stock appearance in order to fool opponents in a drag race, or to avoid the attention of the police. 

  • A small starter earring, worn to prevent a piercing from closing. 

  • Someone who sleeps. 

  • Something that achieves unexpected success after an interval of time. 

  • A structural beam in a floor running perpendicular to both the joists beneath and floorboards above. 

  • A railway sleeping car. 

  • The lowest, or bottom, tier of casks. 

verb
  • To mark a calf by cutting its ear. 

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 sleeper and spy occurred in a corpus of books? (source: Google Ngram Viewer )