Definition of psycho in US English:



  • A psychopath.

    • ‘I don't want to be put in there with a bunch of crazy psychos… I'm not a bad person.’
    • ‘Second, my best friend and crush is being stalked by crazy, murderous psychos.’
    • ‘It's unpleasant, but it's more unpleasant to be faced with true psychos / junkies on the subway.’
    • ‘Kleptomaniacs, kitchen drinkers, Fatal Attraction type psychos, obsessive-compulsives, and other problem individuals are usually discovered in this phase.’
    • ‘The speech was basically: men are psychos, Americans are psychos, the Americans want to exterminate the planet, and naked protest will end the nuclear age.’
    madman, madwoman, mad person, deranged person, maniac, lunatic, psychotic, sociopath
    View synonyms


  • Psychopathic.

    • ‘I love blood and gore and crazed psycho killers come back from the dead.’
    • ‘Next is Melanie, doing that psycho laugh of hers from the old days.’
    • ‘I would come back and watch all my favourite violent psycho movies.’
    • ‘They were scrawny but muscly trashy types, like my in-and-out, in-and-out of prison psycho cousin.’
    • ‘I always thought that those psycho girls who stalked band members and actors were just make believe, until now.’


1930s: abbreviation.