centennium vs cobwebbiness

centennium

noun
  • Synonym of century: A period of 100 years. 

cobwebbiness

noun
  • Oldness; datedness. 

  • The state of having many cobwebs. 

  • The quality of a resemblance to cobwebs. 

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