paranoia Definition

paranoia
noun paranoias

1. psychol.
A rare mental disorder, characterized by delusions of persecution by others, especially if this is attributed to one's own importance or unique gifts.
2. A strong, usually irrational, feeling that one is being persecuted by others, resulting in a tendency to be suspicious and distrustful, and to become increasingly isolated.

Etymology: 19c: Greek, from para- beyond + nous mind.