the officer responsible for the upkeep and maintenance of a warship, esp the executive officer of a smaller ship in the Royal Navy
2.
an officer holding commissioned rank in the US Army, Air Force, Marine Corps, or in certain other forces, senior to a second lieutenant and junior to a captain
first lieutenant in American English
1. US Military
an officer ranking above a second lieutenant and below a captain
2. US Navy
the officer in charge of maintenance of a ship or shore station
Examples of 'first lieutenant' in a sentence
first lieutenant
Tatiana didn't want him to be old enough to be a first lieutenant.