ceaseless vs unendly

ceaseless

adj
  • Without an end. 

  • Without stop or pause, incessant. 

unendly

adj
  • Having no end; infinite; endless; unending. 

adv
  • In an unendly or infinite manner; infinitely; unendingly. 

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