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par⋅a⋅noi⋅a (noun) :

1. baseless or excessive suspicion of the motives of others.
2. Extreme, irrational distrust of others.
3. a tendency on the part of an individual or group toward excessive or irrational suspiciousness and distrustfulness of others

Note: In popular terminology, a “paranoid” personality is characterized by suspicion and distrust of others; a tendency to look for hidden meaning behind other people's actions; argumentativeness; complaining; low tolerance for criticism; and a constant display of one's own talents, accomplishments, independence, and rationality.