threefold vs trigeminous

threefold

adj

  • triple 

  • three times as great 

adv

  • by a factor of three 

verb

  • To make threefold; to triple. 

noun

  • An algebraic variety of dimension 3. 

trigeminous

adj

  • threefold 

  • born three together; being one of three born at the same birth 

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