1. a late-onset psychotic condition that is marked by delusions and hallucinations but is distinct from schizophrenia by virtue of the absence of generalized intellectual impairment and distinct from degenerative dementias by virtue of the absence of a progressively deteriorating course. See also late paraphrenia. [first described by Emil Kraepelin]

2. any of various mental disorders that are associated with transitional periods of life (e.g., adolescence, old age). [defined in 1863 by German physician Karl Ludwig Kahlbaum (1828–1899)]

3. loosely, any of a variety of conditions, such as late-onset schizophrenia, paranoid schizophrenia, or certain paranoid states.