Simple Definition of psycho
: a person who is mentally ill and often dangerous or violent
Full Definition of psychoplural
: a deranged or psychopathic person —not used technically
Examples of psycho in a sentence
He plays a drug-dealing psycho in the movie.
<a story based on a real-life psycho who had serious mother-son issues>
Origin and Etymology of psycho
short for psychopath
First Known Use: 1942
Seen and Heard
What made you want to look up psycho? Please tell us where you read or heard it (including the quote, if possible).