deranged
adj. C1 Advanced US //dɪˈɹeɪndʒd// UK //dɪɹˈeɪndʒd// de·ranged
adj. unable to think or act in a normal or sensible way, often because of mental illness. It describes someone who is behaving in a wild or dangerous manner.
adj. mentally unbalanced or insane; exhibiting extremely irrational or disordered behavior. Often used predicatively after linking verbs like 'become' or 'appear'.
The man looked deranged as he shouted at the empty street.
After weeks of isolation in the wilderness, the survivor appeared slightly deranged to the rescue team.
The antagonist's deranged laughter echoed through the halls, signaling to the audience that he had finally lost his grip on reality.
From French dérangé.
Usage
Typically used as a predicative or attributive adjective to describe a person's mental state or behavior.