concomitance vs pairing

concomitance

noun
  • occurrence or existence together or in connection with one another, coexistence 

  • A concomitant. 

  • The Roman Catholic doctrine of the existence of the entire body of Christ in the Eucharist, under each element, so that the body and blood are both received by communication in one kind only. 

pairing

noun
  • The combination or union of two things. 

  • An agreement between two members of a legislative body holding opposite opinions to refrain from voting, so that both may absent themselves. 

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