Definition of paranoia
1 : mental illness characterized by systematized delusions of persecution or grandeur usually without hallucinations
Psychotic symptoms and paranoia persisted, and she continued to "find clues" of conspiracy against her.— Helen K. Delichatsios et al.
2 : a tendency on the part of an individual or group toward excessive or irrational suspiciousness and distrustfulness of others
The members of America's racist right inhabit a murky world of conspiracy, suspicion, and paranoia.— Wayne King
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Merriam-Webster unabridgedWords at Play
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Time Traveler for paranoia
The first known use of paranoia was in 1887
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