A rank in the British Royal Navy, and the officer who holds it. It sits above a midshipman and below a lieutenant — so a young officer, out of training, given real duties but still learning the job. In Britain it is usually written 'sub-lieutenant', with the hyphen; the solid spelling turns up too, and American writing tends to drop the hyphen. Note that this is a NAVY word. Armies do not have sub-lieutenants in Britain; the army's junior officer is a second lieutenant. Several other countries' navies use the same rank name in English translation (Canada, and older French and Russian ranks are often rendered this way), so you meet it in history books and translated novels more than in daily life. In speech, British sailors say the 'lieutenant' part as 'lef-TEN-ant', not 'loo-TEN-ant'. Outside the navy the word is rare, and it is not a general word for 'assistant' — for that, English uses 'deputy'.

海軍中尉（英國皇家海軍軍階，在上尉 lieutenant 之下）。注意台灣軍階翻譯常隨制度不同而浮動，看到這個字重點是「剛出道的年輕海軍軍官」。