sobriquet

a familiar name for a person (often a shortened version of a persons given name); "Joes mother would not use his nickname and always called him Joseph"; "Henrys nickname was Slim"

उन्होंने प्रसिद्ध मेडिकल कॉलेज से चिकित्सा में उपाधि प्राप्त की।

Addressing Mr Halliday by his sobriquet, he said, Well, King Frederick, I am sorry to hear you have been oppressing some youngster in your service.