Defective and impossible to materially correct or set aright.
Unmanageable.
Impervious to correction by punishment or pain.
Determined, unalterable, hence impossible to improve upon.
Incurably depraved; not reformable.
An incorrigibly bad individual.
Having properties that cause unusually bad behaviour, especially regarding correctness or performance.
Relating to, amounting to, causing, or caused by a physical or mental disorder.
Having properties which are counterintuitive or difficult to handle.
Pertaining to pathology.