continuant vs sempiternal

continuant

adj
  • Continuing; prolonged; sustained. 

noun
  • An endurant. 

  • A determinant formed from a tridiagonal matrix. 

  • A linguistic sound other than a stop. 

sempiternal

adj
  • Everlasting, that is, having infinite temporal duration (as opposed to eternal: outside time and thus lacking temporal duration altogether). 

  • Everlasting, eternal. 

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