A telegraphist was someone whose job was sending and receiving messages by telegraph. It means the same as 'telegrapher' — the difference is only where the word is at home. 'Telegraphist' is the British form, and you meet it especially in British and Commonwealth writing, in the Royal Navy and merchant ships, and in old post office records. 'Telegrapher' is the American form. Neither is more correct; they are two countries' habits. The work: sitting at a key and tapping Morse code, then listening to the incoming clicks and writing them out as words, fast, with no chance to ask for a repeat. It was a trained trade with exams and grades, not casual work. At sea, the ship's telegraphist was the only link to the shore — this is the job people picture when they think of the wireless operators on the Titanic, tapping for help in the dark. The word has a formal, official smell to it, because it lived in navy ranks and government job lists: 'Telegraphist, Second Class'. That is part of why it survives in old documents while ordinary people said 'the telegraph man' or 'the operator'. The job no longer exists, so the word belongs to history now — you meet it in books, museums, war records, and family stories, not in job advertisements.

電報員／報務員（英式用法；船上、海軍的通信兵也用這個詞）。