continual vs continuant

continual

adj
  • Recurring in steady, rapid succession. 

  • Seemingly continuous; appearing to have no end or interruption. 

  • Forming a continuous series. 

continuant

adj
  • Continuing; prolonged; sustained. 

noun
  • An endurant. 

  • A determinant formed from a tridiagonal matrix. 

  • A linguistic sound other than a stop. 

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