three-ply vs trine

three-ply

adj
  • Having three strands or layers 

noun
  • Yarn having three strands 

trine

adj
  • Triple; threefold. 

  • Denoting the aspect of two celestial bodies which are 120° apart. 

noun
  • A group of three things. 

  • An aspect of two astrological bodies when 120° apart. 

verb
  • To put in the aspect of a trine. 

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