psychosis

noun

psy·​cho·​sis sī-ˈkō-səs 

plural psychoses sī-ˈkō-ˌsēz 

: a serious mental illness (such as schizophrenia) characterized by defective or lost contact with reality often with hallucinations or delusions

Examples of psychosis in a Sentence

The patient suffers from some kind of psychosis.

Recent Examples on the Web

Shot locally in Los Angeles and based on an original idea by Nicholas Geisler (Bunk’d), who here made his feature directorial debut, Gulf of America follows a family who inherits a decaying desert motel, triggering an inescapable descent into greed, psychosis, and terror. —Matt Grobar, Deadline, 24 Feb. 2026

The program model gave priority to keeping people on their medications, many of which are monthly shots to guard against psychosis. —Sarah Cutler, Idaho Statesman, 20 Feb. 2026

OpenAI alone admitted that ChatGPT that more than half a million people were having conversations that showed signs of psychosis every week. —Frank Landymore, Futurism, 18 Feb. 2026

Because there's no clear motive in this case, doesn't that support the defense's argument that Connor went into some sort of a psychosis? —Stephanie Slifer, CBS News, 8 Feb. 2026

Word History

Etymology

New Latin

First Known Use

1847, in the meaning defined above

Rhymes for psychosis

• cirrhosis
• fibrosis
• gliosis
• hypnosis
• ichthyosis
• ketosis
• kurtosis
• lordosis
• meiosis
• miosis
• mitosis
• mycosis

Kids Definition

psychosis

noun

psy·​cho·​sis sī-ˈkō-səs 

plural psychoses -ˈkō-ˌsēz 

: a serious mental illness marked by loss of or greatly lessened ability to test whether what one is thinking and feeling about the real world is really true

Medical Definition

psychosis

noun

psy·​cho·​sis sī-ˈkō-səs 

plural psychoses -ˌsēz 

: a serious mental illness (as schizophrenia) characterized by defective or lost contact with reality often with hallucinations or delusions