The obsolete name for a psychotic disorder, now called delusional disorder, often (in one of 6 subtypes) characterized by delusions of persecution and perceived threat against the individual affected with the disorder, and often associated with false accusations and general mistrust of others

plural of paranoia

Pertaining to, or exhibiting, paranoia.

Somebody who has paranoia, a paranoid person.

plural of paranoiac

Resembling or characteristic of paranoia.

In a paranoiac way.