paranoid

Universal Words adjective, noun adjective (also less frequent paranoiac ) 1 afraid or suspicious of other people and believing that they are trying to harm you, in a way that is not reasonable: She's getting really paranoid about what other people say about her. 2 suffering from a mental illness in which you wrongly believe that other people are trying to harm you or that you are very important: paranoid delusions * paranoid schizophrenia * a paranoid killer noun (also paranoiac ) a person who suffers from paranoia