implacable

Impossible to placate or appease.

Not placable; not to be appeased; not to be pacified or reconciled; inexorable.

Not to be relieved or assuaged.

Synonyms Relentless, etc. (see inexorable), unappeasable, unforgiving, vindictive, pitiless, rancorous.

Not placable; not to be appeased; incapable of being pacified; inexorable.