Definitions of unacceptable:

• adjective:   not adequate to give satisfaction

  Example: "The coach told his players that defeat was unacceptable"

• adjective:   not conforming to standard usage

  Example: "The following use of `access' was judged unacceptable by a panel of linguists"

• adjective:   not acceptable; not welcome

  Example: "A word unacceptable in polite society"

• adjective:   used of persons or their behavior