Main entry: unpronounceable, unutterable
Definition: very difficult to pronounce correctly
Usage: an unpronounceable foreign word; unutterable consonant clusters
Main entry: unspeakable, untellable, unutterable, indefinable, indescribable, ineffable
Definition: defying expression or description
Usage: indefinable yearnings; indescribable beauty; ineffable ecstasy; inexpressible anguish; unspeakable happiness; unutterable contempt; a thing of untellable splendor
Main entry: unnameable, unspeakable, unutterable, ineffable
Definition: too sacred to be uttered
Usage: the ineffable name of the Deity