To be brief means to be short in duration or length. A brief conversation lasts only a few minutes. A brief note contains just a sentence or two instead of paragraphs. When your teacher asks for a brief summary of a book, they want the main points without unnecessary details.

The word carries a sense of purpose and efficiency. Something brief doesn't waste time or space. A brief explanation gets straight to the point. A brief visit means you're not staying long. When someone says “to be brief” or “in brief,” they're signaling they'll summarize quickly.

Brief can also be a verb meaning to give someone essential information efficiently. A coach might brief the team before a game, explaining the strategy in a few focused minutes. Military officers brief their troops, and lawyers brief their clients.

Brief can also be a noun. In law, a brief is a written document that explains the main points of a case. In everyday speech, someone might say, “Here's the brief,” meaning a short summary of important information.

The opposite of brief is lengthy, long-winded, or drawn-out. When you're running late and someone asks what happened, they probably want a brief explanation, not your entire morning routine described minute by minute.