1. (adj)unacceptable not adequate to give satisfaction
"the coach told his players that defeat was unacceptable"
2. (adj)unacceptable not acceptable; not welcome
"a word unacceptable in polite society"; "an unacceptable violation of personal freedom"
3. (adj)impossible, insufferable, unacceptable, unsufferable used of persons or their behavior
"impossible behavior"; "insufferable insolence"
4. (adj)unacceptable, unaccepted 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'"