[syn: unacceptable, unaccepted]
The Collaborative International Dictionary of English v.0.48:
Unacceptable \Un`ac*cept"a*ble\, a.
   Not acceptable; not pleasing; not welcome; unpleasant;
   disagreeable; displeasing; offensive. --
   Un`ac*cept"a*ble*ness, n. -- Un`ac*cept"a*bly, adv.
   [1913 Webster]
WordNet (r) 3.0 (2006):
unacceptable
    adj 1: not adequate to give satisfaction; "the coach told his
           players that defeat was unacceptable"
    2: not acceptable; not welcome; "a word unacceptable in polite
       society"; "an unacceptable violation of personal freedom"
       [ant: acceptable]
    3: used of persons or their behavior; "impossible behavior";
       "insufferable insolence" [syn: impossible, insufferable,
       unacceptable, unsufferable]
    4: not conforming to standard usage; "the following use of
       `access' was judged unacceptable by a panel of linguists;
       `You can access your cash at any of 300 automatic tellers'"
       [syn: unacceptable, unaccepted]
Moby Thesaurus II by Grady Ward, 1.0:
30 Moby Thesaurus words for "unacceptable":
   bad, disagreeable, discommendable, distasteful, exceptionable,
   ill-favored, illaudable, impossible, improper, inadmissible,
   inappropriate, indefensible, intolerable, objectionable, tasteless,
   unagreeable, unallowable, unasked, unbidden, uncommendable,
   undesirable, uninvited, unpleasant, unpraiseworthy, unsatisfactory,
   unsuitable, untenable, unwanted, unwelcome, wrong