In informal English, a psycho is someone people call mentally ill and dangerous — violent, or acting in a very strange way. Crime films use it a lot.

In informal English在非正式英文裡，a psycho psycho is someone people call mentally ill and dangerous是人們用來稱呼精神有問題又危險的人——violent, or acting in a very strange way很暴力，或行為非常怪異。Crime films犯罪電影 use it a lot很常用它。

Though actually this is not a doctor’s word. No psychiatrist writes psycho on a chart. It is slang, and it is often cruel. Using it about a real person is usually an insult, and a wrong picture of someone who is ill.

Though actually不過實際上 this is not a doctor's word這不是醫生用的詞。No psychiatrist沒有精神科醫生 writes psycho on a chart會在病歷上寫psycho。It它 is slang是俚語，and it is often cruel而且常常很傷人。Using it about a real person拿它來講一個真實的人 is usually an insult通常是一種侮辱，and a wrong picture of someone who is ill也是對生病的人一種錯誤的描繪。

Younger speakers also throw it around as a joke — “You’re psycho!” — just meaning “That was a wild thing to do,” with no illness in sight. You will also hear it before a noun: a psycho killer.

Younger speakers also throw it around as a joke — "You're psycho!"年輕的說話者也會開玩笑地亂用——「你是psycho！」——just meaning "That was a wild thing to do"只是意思是「那件事做得太瘋狂了」，with no illness in sight跟疾病一點關係都沒有。You will also hear it before a noun你也會聽到它放在名詞前面：a psycho killera psycho killer。

It is a short, rough clip of psychotic or psychopath, with the slang ending -o, the same kind of ending as in sicko.

It它 is a short, rough clip of psychotic or psychopath是psychotic或psychopath簡略、粗略剪短的版本，with the slang ending -o帶著俚語的-o字尾，the same kind of ending as in sicko跟sicko裡的字尾是同一種。