[syn: ineffable, unnameable, unspeakable, unutterable]
The Collaborative International Dictionary of English v.0.48:
Unspeakable \Unspeakable\
   See speakable.
The Collaborative International Dictionary of English v.0.48:
Unspeakable \Un*speak"a*ble\, a. [Pref. un- not + speakable.]
   Not speakable; incapable of being uttered or adequately
   described; inexpressible; unutterable; ineffable; as,
   unspeakable grief or rage. -- Un*speak"a*bly, adv.
   [1913 Webster]
         Ye rejoice with joy unspeakable and full of glory. --1
                                                  Pet. i. 8.
   [1913 Webster]
WordNet (r) 3.0 (2006):
unspeakable
    adj 1: defying expression or description; "indefinable
           yearnings"; "indescribable beauty"; "ineffable ecstasy";
           "inexpressible anguish"; "unspeakable happiness";
           "unutterable contempt"; "a thing of untellable splendor"
           [syn: indefinable, indescribable, ineffable,
           unspeakable, untellable, unutterable]
    2: exceptionally 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" [syn:
       atrocious, abominable, awful, dreadful, painful,
       terrible, unspeakable]
    3: too sacred to be uttered; "the ineffable name of the Deity"
       [syn: ineffable, unnameable, unspeakable,
       unutterable]
Moby Thesaurus II by Grady Ward, 1.0:
127 Moby Thesaurus words for "unspeakable":
   abominable, abusive, appalling, arrant, atrocious, awesome, awful,
   backhand, backhanded, bad, baneful, base, beastly, black, blamable,
   blameworthy, calumnious, contumelious, criminal, damnable, dark,
   degrading, detestable, dire, disgraceful, disgusting, distasteful,
   divine, dreadful, evil, exceptional, execrable, extraordinary,
   fabulous, flagitious, flagrant, foul, grim, hateful, heavenly,
   heinous, hideous, holy, horrendous, horrible, horrid, horrific,
   horrifying, humiliating, improper, incommunicable, indefinable,
   indescribable, ineffable, inenarrable, inexpressible, infamous,
   iniquitous, innominable, insolent, insulting, inviolable,
   inviolate, knavish, left-handed, legendary, loathsome, low,
   marvelous, monstrous, mythical, naughty, nefarious,
   noncommunicable, noteworthy, numinous, obnoxious, odious,
   offensive, outrageous, peccant, phenomenal, portentous, prodigious,
   rank, religious, remarkable, repellent, reprehensible, reprobate,
   repugnant, repulsive, revolting, rotten, sacred, sacrosanct,
   scandalous, scurrile, scurrilous, shameful, shocking, sinful,
   spiritual, stupefying, stupendous, terrible, tragic, undefinable,
   unexampled, unforgivable, unmentionable, unnameable, unparalleled,
   unpardonable, unprecedented, untellable, untouchable, unutterable,
   unwhisperable, unworthy, venerable, vicious, vile, villainous,
   wicked, wonderful, wrong