continual vs relentless

continual and relentless both are adjectives.

Word	Noun	Adjective	Verb	Adverb
continual	No	Yes	No	No
relentless	No	Yes	No	No

continual (adjective)	relentless (adjective)
recurring regularly or frequently in a prolonged and closely spaced series	never-ceasing
having no interruptions	not to be placated or appeased or moved by entreaty