The senior grade of lieutenant is known as first lieutenant in the United States, and as lieutenant in the United Kingdom and the rest of the English-speaking world.

In English, lieutenant is best known as a military title, but the word is still sometimes used in its original meaning to refer to a person who acts in lieu of someone else.

Lieutenant, company grade officer, the lowest rank of commissioned officer in most armies of the world. The lieutenant normally commands a small tactical unit such as a platoon.

/ luˈten·ənt / Add to word list a naval officer of middle rank, above an ensign; or a military officer of the lowest rank (Definition of lieutenant from the Cambridge Academic Content Dictionary © …

If you refer to someone as a person's lieutenant, you mean they are that person's assistant, especially their main assistant, in an organization or activity. He was my right-hand man, my …

Definition of lieutenant noun in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more.

lieutenant noun A person who holds a position auxiliary to another and assumes some of the superior's responsibilities:

Nov 4, 2025 · (military, US) In the US Army, Air Force and Marines, holding the rank above second lieutenant and below captain. Both ranks may be referred to as " lieutenant" or as the …

So a lieutenant is a placeholder, one who takes the place or of or is deputy to a superior officer. In non-military contexts, lieutenant is a synonym of assistant or deputy. In the U.S. military, a …

Lieutenant general (United States) ... In the United States Armed Forces, a lieutenant general is a three-star general officer in the United States Army, Marine Corps, Air Force, and Space …