unsayable

un say a ble |ˌənˈsāəbəl ənˈseɪəbəl | ▶adjective not able to be said, esp. because considered too controversial or offensive to mention.

unsayable

un |say ¦able |ʌnˈseɪəb (ə )l | ▶adjective not able to be said, especially because considered too controversial or offensive to mention.