continuous vs relentless

continuous

adj
  • Without stopping; without a break, cessation, or interruption. 

  • Expressing an ongoing action or state. 

  • Not deviating or varying from uniformity; not interrupted; not joined or articulated. 

  • Such that, for every x in the domain, for each small open interval D about f(x), there's an interval containing x whose image is in D. 

  • Without intervening space; continued. 

  • Such that each open set in the target space has an open preimage (in the domain space, with respect to the given function). 

relentless

adj
  • Unremitting, steady and persistent. 

  • Unrelenting or unyielding in severity. 

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