ineffable ineffable /ˌɪˈnɛfəbəl/

adjective

1. () Defying expression or description  ( indefinable , unutterable , undescribable , indescribable , ineffable , unspeakable , untellable )
   defying expression or description
    Indefinable yearnings
   indefinable yearnings
    Indescribable beauty
   indescribable beauty
    Ineffable ecstasy
   ineffable ecstasy
    Inexpressible anguish
   inexpressible anguish
    Unspeakable happiness
   unspeakable happiness
    Unutterable contempt
   unutterable contempt
    A thing of untellable splendor
   a thing of untellable splendor
   
2. Too sacred to be uttered  ( ineffable , unnameable , unspeakable , unutterable , unsayable )
   too sacred to be uttered
    The ineffable name of the Deity
   the ineffable name of the Deity