This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. That cannot or must not be uttered or expressed: "I burned in the unutterable beauty of being alive” ( John Peale Bishop). See Synonyms at unspeakable.

adj. Being such that pronunciation is impossible: unutterable consonant clusters.

adj. Not utterable; incapable of being spoken or voiced; inexpressible; ineffable; unspeakable.

adj. Not utterable; incapable of being spoken or voiced; inexpressible; ineffable; unspeakable.

Incapable of being uttered or expressed; ineffable; inexpressible; unspeakable: as, unutterable anguish; unutterable joy.

adj. very difficult to pronounce correctly

adj. too sacred to be uttered

adj. defying expression or description

"Elohim, etc., and still less Yahweh, the ineffable name, i.e. a name unutterable to any human tongue; instead of these, they used metaphors or expressions having reference to the Divine attributes."

incommunicative    uncommunicative    sacred    unexpressible    inexpressible   

inexpressible    abominable   

unutterably    unutterableness   

inexpressible    ineffable    unspeakable    incommunicable    indescribable   

inexpressible    utter    undisguised    unbearable    inward    overwhelm    unfeigned    speechless    unmitigated    immeasurable