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

Prosecutors say the murders were calculated, while Clancy's defense argues that she was overmedicated and suffering from extreme postpartum psychosis. — Penny Kmitt, CBS News, 31 July 2026

But, Moon says, treatments that doctors rely on to help people with postpartum psychosis may be similar to those used for other kinds of psychosis. — Jackie Flynn Mogensen, Scientific American, 31 July 2026

Postpartum Support International states that 4% of postpartum psychosis sufferers commit infanticide, and 5% die by suicide. — Charles Trepany, USA Today, 30 July 2026

However, Lindsay’s attorney, Kevin Reddington, has maintained that his client was suffering from severe postpartum depression and undiagnosed postpartum psychosis. — Caroline Blair, PEOPLE, 27 July 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