Open English Wordnet
Adjectives
(s)indefinable, indescribable, ineffable, unspeakable, untellable, unutterabledefying expression or description“indefinable yearnings”, “indescribable beauty”, “ineffable ecstasy”, “unspeakable happiness”, “unutterable contempt”, “a thing of untellable splendor”
(s)atrocious, abominable, awful, dreadful, painful, terrible, unspeakableexceptionally 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”
(s)ineffable, unnameable, unspeakable, unutterabletoo sacred to be uttered“the ineffable name of the Deity”