C2 noun /ˌpærəˈnɔɪæk/
paranoiac
パラノイア的な人
Meaning
A person who suffers from paranoia or exhibits extreme, irrational distrust and suspicion.
Example
The paranoiac refused to leave his house, fearing everyone was against him.
そのパラノイア的な人は、みんなが自分に反対していると恐れて家を出ることを拒んだ。