castling vs substitution

castling

noun
  • A miniature cast or mould. 

  • One that is cast. 

  • The act of constructing a defense structure in Japanese chess in which the king (玉) is positioned in a certain way so that it is protected by pawns (歩) and silver general(s) (銀) and/or gold general(s) (金) often with an additional knight (桂) and lance (香車). 

  • A move in which the king moves two squares towards a rook, and the rook moves to the other side of the king; the action of the verb to castle. 

substitution

noun
  • A substitute or replacement. 

  • The act of substituting or the state of being substituted. 

  • The expansion of the lexicon of a language by native means in correspondence to a foreign term. 

  • The replacement of an atom, or group of atoms, in a compound, with another. 

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