septenary vs septuplet

septenary

noun
  • A group of seven things. 

  • A period of seven years. 

  • The seven notes of the diatonic scale. 

adj
  • Of seventh rank or order. 

  • Consisting of or containing seven. 

  • Lasting seven years; continuing seven years. 

septuplet

noun
  • A group of seven, particularly (music) a tuplet of seven notes. 

  • One of a group of seven, particularly one of seven babies born at the same birth. 

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