synod vs upper chamber

synod

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

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

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

  • 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 

upper chamber

noun
  • The upper legislative chamber in a bicameral legislature; usually smaller and having more restricted power than the lower chamber. 

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