ternion vs trinity

ternion

noun
  • The number three; three things together; a ternary or triplet. 

  • A section of paper for a book containing three double leaves or twelve pages. 

trinity

noun
  • The state of being three; independence of three things; things divided into three. 

  • A group or set of three people or things; three things combined into one. 

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