unappeasable vs relentless

unappeasable and relentless both are adjectives.

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

As adjectives, unappeasable and relentless are synonyms defined as:

unappeasable and relentless: not to be placated or appeased or moved by entreaty

Other synonyms of unappeasable include grim, inexorable, stern, unforgiving, unrelenting.

unappeasable (adjective)	relentless (adjective)
not to be placated or appeased or moved by entreaty	never-ceasing
	not to be placated or appeased or moved by entreaty