schizophrenia

noun

1. a major mental disorder of unknown cause typically characterized by a separation between the thought processes and the emotions, a distortion of reality accompanied by delusions and hallucinations, a fragmentation of the personality, motor disturbances, bizarre behavior, etc., often with no loss of basic intellectual functions: this term has largely replaced dementia praecox, since it does not always result in deterioration (dementia) or always develop in adolescence or before maturity (praecox)
2. multiple personality disorder
3. Informal a situation, state of mind, etc. in which widely conflicting opinions, ideas, or practices coexist, often resulting in indecision, vacillation, wavering, etc.

Origin: ModL < schizo- + Gr phrēn, the mind + -ia