alienist /'eihanist; 'eljamst/ n 1 (US) expert on the mental competence of witnesses in a law court. (美) 鑒定出庭之證人其心智是否能適任作證之專家。 2 (old use) specialist in mental illness (now called a psychiatrist). (舊用法) 精神病醫(yī)生; 精神病學(xué)家 (現(xiàn)稱作 psychiatrist)。