Unspeakable
Pronunciation : Un*speak"a*ble
Part of Speech : a.
Etymology : [Pref. un- not + speakable.]
Definition : Defn: Not speakable; incapable of being uttered or adequately described; inexpressible; unutterable; ineffable; as, unspeakable grief or rage. -- Un*speak"a*bly, adv. Ye rejoice with joy unspeakable and full of glory. 1 Pet. i. 8.
Source : Webster's Unabridged Dictionary, 1913