Definitions

1. noun

A person who is considered to be extremely unstable or unpredictable in their behavior.

“The movie was about a serial killer who was considered a psycho by the police.”

2. adjective

Relating to or characteristic of a psycho.

“The psycho killer in the movie was known for his extreme brutality.”

3. adverb

In a manner that is characteristic of a psycho.

“He acted psycho, running wildly through the streets without any reason.”