A moment means a brief period of time, usually just seconds or minutes. When your teacher says “wait a moment,” she means a very short time. When you capture a special moment in a photograph, you're freezing a specific instant that matters to you.

The word suggests something fleeting but significant. A moment of silence at a memorial lasts only seconds, but carries deep meaning. A moment of truth is when something important gets decided quickly. Athletes train for years to perform well in the crucial moments of competition.

We use moment differently than words like “hour” or “day” because it emphasizes how quickly time passes. The moment you finish reading this sentence, it becomes the past. Parents tell children to “live in the moment,” meaning pay attention to what's happening right now instead of worrying about yesterday or tomorrow.

In physics and engineering, a moment has a technical meaning: it's a measure of the turning effect of a force on an object, like when you push on a door handle to make it swing open. The farther from the hinge you push, the greater the moment.

The phrase “at the moment” means right now: “I'm busy at the moment, but I can help you later.”