Midshipman

1. During the 17th century, a naval rating for an experienced seaman.
2. From the 18th century, a naval commissioned officer candidate.
3. From the 1790s, an apprentice naval officer.
4. From the 19th century, an officer cadet at a naval academy.
5. In contemporary British usage, a non-commissioned officer below the rank of lieutenant. Usually regarded as being "in training" to some degree. Also known as "Snotty". It is "the lowest form of rank in the Royal Navy" where he has authority over and responsibility for more junior ranks, yet, at the same time, relying on their experience and learning his trade from them.
6. In contemporary American usage, a cadet of either sex at the United States Merchant Marine Academy or the United States Naval Academy, or under contract and having sworn the Oath of Office in the Navy Reserve Officer Training Corps (NROTC) program. When plural (midshipmen), the term refers to the student body of either academy, and more formally as "the Regiment of Midshipmen" for the Merchant Marine Academy and "the Brigade of Midshipmen" for the Naval Academy, or for the NROTC unit members usually organized into battalions.