a person who is mentally ill and who behaves in a very strange violent way 精神病患者；精神病人 In his new film, he plays the part of a crazed psycho. 在他的新电影中，他扮演着疯狂的心理角色。 Don’t let him drive—he’s a complete psycho behind the wheel! 别让他开车-他是方向盘上的一个完整的心理人物！
Word Origin1930s: abbreviation.