derivable vs eternal

derivable

adj
  • able to be derived, deducible 

eternal

adj
  • existing outside time; as opposed to sempiternal, existing within time but everlastingly 

  • Lasting forever; unending. 

  • Constant; perpetual; ceaseless; ever-present. 

noun
  • One who lives forever; an immortal. 

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