primary vs substitute

primary

verb
  • To challenge (an incumbent sitting politician) for their political party's nomination to run for re-election, through running a challenger campaign in a primary election, especially one that is more ideologically extreme. 

  • To take part in a primary election. 

adj
  • Earliest formed; fundamental. 

  • first or earliest in a group or series. 

  • main; principal; chief; placed ahead of others. 

  • Relating to day-to-day care provided by health professionals such as nurses, general practitioners, dentists etc. 

  • Relating to the place where a disorder or disease started to occur. 

  • Illustrating, possessing, or characterized by, some quality or property in the first degree; having undergone the first stage of substitution or replacement. 

noun
  • A directly driven inductive coil, as in a transformer or induction motor that is magnetically coupled to a secondary 

  • A primary school. 

  • A primary election; a preliminary election to select a political candidate of a political party. 

  • A radar return from an aircraft (or other object) produced solely by the reflection of the radar beam from the aircraft's skin, without additional information from the aircraft's transponder. 

  • Any flight feather attached to the manus (hand) of a bird. 

  • A base or fundamental component; something that is irreducible. 

  • The most massive component of a gravitationally bound system, such as a planet in relation to its satellites. 

  • The first year of grade school. 

  • A primary colour. 

  • Primary site of disease; original location or source of the disease. 

  • The first stage of a thermonuclear weapon, which sets off a fission explosion to help trigger a fusion reaction in the weapon's secondary stage. 

substitute

noun
  • A player who is available to replace another if the need arises, and who may or may not actually do so. 

  • A replacement or stand-in for something that achieves a similar result or purpose. 

  • One who enlists for military service in the place of a conscript. 

verb
  • To remove (a player) from the field of play and bring on another in his place. 

  • To serve as a replacement (for someone or something). 

  • To use in place of something else, with the same function. 

  • To use X in place of Y. 

  • To use Y in place of X; to replace X with Y. 

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