aeviternity vs eon

aeviternity

noun
  • Synonym of eternity (“existence without end”) 

  • Synonym of aevum (“the temporal mode of existence between time and eternity, said to be experienced by angels, saints, and celestial bodies (which medieval astronomy believed to be unchanging)”) 

eon

noun
  • Eternity. 

  • A period of 1,000,000,000 years. 

  • The longest geochronologic unit, being a period of hundreds of millions of years; subdivided into eras. 

  • A spirit being emanating from the Godhead. 

  • A long period of time. 

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