Pronunciation: (sī-kō'sis), [key]
—pl. -sesPronunciation: (-sēz). [key]
1. a mental disorder characterized by symptoms, such as delusions or hallucinations, that indicate impaired contact with reality.
2. any severe form of mental disorder, as schizophrenia or paranoia.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.