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

As an additional important benefit, when the Islamic world sees that Hamas has lost its hold on the Strip and that the nightmare of Hamas has been replaced with a new reality of peace and prosperity, the suicidal psychosis of radical Islam will suffer a crushing blow. —David Friedman, Newsweek, 10 Feb. 2025

Unlike Celeste, and unlike Howard Roark in Ayn Rand’s The Fountainhead, who stood for the artist’s right to individual integrity, Toth’s psychosis derives from a pessimistic view of history. —Armond White, National Review, 3 Jan. 2025

Stone’s feature describes how psychiatrists and neurologists are now coming together to find patients whose psychosis traces to antibodies that have turned their attack on key brain proteins. —Christie Wilcox, science.org, 27 Dec. 2024

The authors pointed out, a little optimistically perhaps, that people in the grip of intense psychosis were highly visible, and urged city officials to get them off the subway. —Keith Gessen, The New Yorker, 28 Jan. 2025

Word History

Etymology

New Latin

First Known Use

1847, in the meaning defined above

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