Impacable
Pronunciation : Im*pa"ca*ble
Part of Speech : a.
Etymology : [L. pref. im- not + pacare to quiet. See Pacate.]
Definition : Defn: Not to be appeased or quieted. [Obs.] Spenser. -- Im*pa"ca*bly, adv.
Source : Webster's Unabridged Dictionary, 1913