impermissibleim‧per‧mis‧si‧ble /ˌɪmpɜːˈmɪsəbəl $ -ɜːr-/ adjective formal 
 
- The conduct of the officers in this case was impermissible.
 
- Codes of conduct were beginning to emerge and a range of permissible and impermissible subjects was being informally drawn up.
 - I consider that such doctrine would be dangerous and impermissible.
 - To switch off the respirator otherwise is impermissible.
 
  nounpermissionpermitpermissivenessadjectivepermissible ≠ impermissiblepermissiveverbpermit