ternion vs threefold

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. 

threefold

noun
  • An algebraic variety of dimension 3. 

adj
  • triple 

  • three times as great 

verb
  • To make threefold; to triple. 

adv
  • by a factor of three 

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