once vs trebly

once

conj
  • As soon as; when; after. 

adv
  • Multiplied by one: indicating that a number is multiplied by one. 

  • One and only one time. 

  • Formerly; during some period in the past. 

trebly

adj
  • Having treble, or high-pitched, qualities. 

adv
  • To three times the extent or degree; triply. 

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