A meter is a unit of length in the metric system, equal to about 3.3 feet or a bit longer than a yardstick. Scientists and most countries use meters to measure distances: a doorway might be two meters tall, or a swimming pool twenty-five meters long. In the United States, we typically use feet and inches instead, but meters appear in science class, international sports, and when measuring long distances (a kilometer is 1,000 meters).

The word also describes the rhythm pattern in poetry and music. When a poem has meter, its syllables follow a regular beat, like the steady rhythm you tap your foot to. Shakespeare wrote in a meter called iambic pentameter, which sounds like a heartbeat: da-DUM da-DUM da-DUM da-DUM da-DUM. Songs have meter too: the repeating pattern of strong and weak beats that makes you want to clap along.

A meter can also be a device that measures something, like a parking meter that tracks time or a gas meter that measures how much natural gas your house uses. When you combine meter with other words, you get instruments like a thermometer (measures temperature) or a speedometer (measures speed).