Mass vs communion

Mass

noun
  • The principal liturgical service of the Church, encompassing both a scripture service (Liturgy of the Word) and a eucharistic service (Liturgy of the Eucharist), which includes the consecration and oblation (offering) of the host and wine. 

  • A similar ceremony offered by a number of Christian churches. 

  • A musical composition set to portions of the Mass. 

communion

noun
  • A form of ecclesiastical unity between the Roman Church and another, so that the latter is considered part of the former. 

  • A joining together of minds or spirits; a mental connection. 

  • Holy Communion. 

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