The Collaborative International Dictionary
Unutterableness
Unutterable \Un*ut"ter*a*ble\, a. Not utterable; incapable of being spoken or voiced; inexpressible; ineffable; unspeakable; as, unutterable anguish.
Sighed and looked unutterable things.
--Thomson.
[1913 Webster] -- Un*ut"ter*a*ble*ness, n. --
Un*ut"ter*a*bly, adv.
Wiktionary
unutterableness
n. The state or condition of being unutterable.