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

Andrea had previously been diagnosed with postpartum depression and postpartum psychosis, which can cause hallucinations and delusions, per the Cleveland Clinic. —Jordana Comiter, PEOPLE, 13 Jan. 2026

The sight of encampments and people in the throes of psychosis in the streets drives perceptions of lawlessness and danger, studies show. —Sonja Sharp, Los Angeles Times, 9 Jan. 2026

Additionally, midway through Act II, there is a shocking set change that reveals just how deep into their psychosis Agnes and Peter have sunk. —Aramide Tinubu, Variety, 9 Jan. 2026

Investors will likely have questions about the upcoming Alzheimer's psychosis trials – called the ADEPT program – for Bristol Myers Squibb's Cobenfy, a prescription medication approved in late 2024 for treating adults with schizophrenia. —Annika Kim Constantino, CNBC, 9 Jan. 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