symposium vs synod

symposium

noun
  • A conference or other meeting for discussion of a topic, especially one in which the participants make presentations. 

  • A drinking party in Ancient Greece, especially one with intellectual discussion. 

  • A collection of essays, articles or papers on a particular subject by a number of contributors. 

synod

noun
  • An ecclesiastic council or meeting to consult on church matters. 

  • A conjunction of two or more of the heavenly bodies. 

  • An administrative division of churches, either the entire denomination, as in the Lutheran Church–Missouri Synod, or a mid-level division (middle judicatory, district) as in the Evangelical Lutheran Church in America 

  • An assembly or council having civil authority; a legislative body. 

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