unspeakable

adjective

1. defying expression or description

- unspeakable happiness

Similar word(s): inexpressible, unexpressible, indefinable, indescribable, ineffable, untellable, unutterable

2. exceptionally bad or displeasing

- an unspeakable odor came sweeping into the room

Similar word(s): bad, abominable, atrocious, awful, dreadful, painful, terrible

3. too sacred to be uttered

Similar word(s): sacred, ineffable, unnameable, unutterable