Implacable :: Implacable (a.) Not placable; not to be appeased; incapable of being pacified; inexorable; as, an implacable prince..
Implacable :: Implacable (a.) Incapable of ebign relieved or assuaged; inextinguishable.
Implacableness :: Implacableness (n.) The quality of being implacable; implacability.