ternion vs three-way

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. 

three-way

noun
  • Sexual activity involving three persons; a threesome; a ménage à trois. 

  • A serving of Cincinnati chili with spaghetti and cheese. 

adj
  • Relating to three different directions. 

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