UNSPEAKABLE

indefinable, indescribable, ineffable, unspeakable, untellable, unutterable

(adjective) defying expression or description; “indefinable yearnings”; “indescribable beauty”; “ineffable ecstasy”; “inexpressible anguish”; “unspeakable happiness”; “unutterable contempt”; “a thing of untellable splendor”

atrocious, abominable, awful, dreadful, painful, terrible, unspeakable

(adjective) exceptionally bad or displeasing; “atrocious taste”; “abominable workmanship”; “an awful voice”; “dreadful manners”; “a painful performance”; “terrible handwriting”; “an unspeakable odor came sweeping into the room”

ineffable, unnameable, unspeakable, unutterable

(adjective) too sacred to be uttered; “the ineffable name of the Deity”

Source: WordNet® 3.1

Etymology

Adjective

unspeakable (comparative more unspeakable, superlative most unspeakable)

Incapable of being spoken or uttered

Synonyms: unutterable, ineffable, inexpressible

Unfit or not permitted to be spoken or described.

Extremely bad or objectionable.

Synonyms

• See also indescribable

Source: Wiktionary

Un*speak"a*ble, a. Etym: [Pref. un- not + speakable.]

Definition: 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 Edition