IMPLA'CABLE, adjective [French from Latin implacabilis; in and placabilis, from placo, to appease.]
1. Not to be appeased; that can not be pacified and rendered peaceable; inexorable; stubborn or constant in enmity; as an implacable prince.
2. Not to be appeased or subdued; as implacable anger; implacable enmity, malice or revenge.