relentless vs unappeasable

relentless and unappeasable both are adjectives.

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

As adjectives, relentless and unappeasable are synonyms defined as:

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

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

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