preliminary vs preparation

preliminary

noun
  • A preparation for a main matter; an introduction. 

  • Any of a series of sports events that determine the finalists 

  • A relatively minor contest that precedes a major one, especially in boxing 

adj
  • In preparation for the main matter; initial, introductory, preparatory. 

preparation

noun
  • The act of preparing or getting ready. 

  • The day before the Sabbath or other Jewish feast-day. 

  • A substance, especially a remedy, that is prepared. 

  • The state of being prepared; readiness. 

  • Devotional exercises introducing an office. 

  • Any of the objects placed between the strings of a prepared piano. 

  • The previous introduction, as an integral part of a chord, of a note continued into a succeeding dissonance. 

  • A part of any animal body preserved as a specimen. 

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