threefold vs trinary

threefold

noun

  • An algebraic variety of dimension 3. 

adj

  • triple 

  • three times as great 

adv

  • by a factor of three 

verb

  • To make threefold; to triple. 

trinary

noun

  • a trinary star 

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