English Reference

Word

psycho

Phoneticspsy·cho

US/ˈsaɪkoʊ/

UK/sˈaɪkəʊ/

Definitions

01a dangerous or unstable person

B2

n. a person who acts in a very strange, violent, or scary way.

n. a person perceived as being mentally unstable, aggressive, or dangerously unpredictable.

“Stay away from him; he acts like a total psycho when he gets angry.”

“The tabloid media was quick to label the suspect a psycho, focusing on his erratic behaviour rather than the underlying social causes of the incident.”

Informal · Slang

Teaching tip

This word is often considered offensive or insensitive because it trivialises mental health issues; use it with caution.

02crazy or scary

C1

adj. behaving in a way that is crazy, scary, or out of control.

adj. exhibiting behaviour that is perceived as psychotic, irrational, or dangerously unstable.

“She has a psycho ex-boyfriend who keeps calling her from different numbers.”

“His psycho reaction to a minor traffic disagreement left the other drivers in the car park feeling genuinely threatened.”

Informal · Slang

Antonyms

03psychology class

C1

n. a short way of saying 'psychology' when talking about a school or university subject.

n. an informal, uncountable shorthand for the academic discipline or a specific course in psychology.

“I have my psycho 101 exam tomorrow morning, so I need to study tonight.”

“Most students in the psycho department found the introductory lectures on behavioural patterns surprisingly challenging.”

Informal · American English

Usage

This sense is typically uncountable and used primarily in student contexts.

Synonyms

Etymology

Clipping of psychotic or psychopath + -o (“person with characteristic”). Compare sicko.

Clipping of psychology.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

The word in film

Poster for Psycho

Poster: Public domain, via Wikimedia Commons.

Psycho · 1960 · Mystery

Directed by:
Alfred Hitchcock
Starring:
Anthony Perkins, Janet Leigh, Martin Balsam

Alfred Hitchcock directed this famous horror mystery about a quiet hotel owner who hides a dark and violent personality. The title describes a dangerous person who behaves in a very scary and unpredictable way.

This entry

Level
C1 · Advanced
Frequency
Frequent
Updated

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English Reference