eternal vs unplumbed

eternal

noun
  • One who lives forever; an immortal. 

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

  • Lasting forever; unending. 

  • Constant; perpetual; ceaseless; ever-present. 

unplumbed

adj
  • Not measured for depth, with or as if with a plumb. 

  • Not assayed or measured in any way. 

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