What is the definition or description of: paranoid?

A type of fear: Someone who fears others mean to harm him/her in some way. They may believe or think others are spying on them or plotting to kill them. When the fear is totally irrational and without basis it may be delusional and psychotic in nature.

Paranoid: Having irrational thought processes, such as belief of being conspired against or persecuted or referenced with special meaning. Can be seen in paranoid personality disorder, paranoid schizophrenia, mood disorders with psychotic features, or substance-induced organic psychoses.