A readout is information displayed by a machine or device, usually in the form of numbers, words, or symbols that tell you what's happening. When you step on a digital scale, the readout shows your weight. When a scientist uses a thermometer to measure the temperature of a chemical reaction, she checks the readout to see if it's getting too hot.

Modern readouts appear on screens, but older devices used mechanical displays with spinning numbers or moving needles. A car's speedometer gives you a readout of how fast you're traveling. A heart rate monitor provides a readout of your pulse. The word emphasizes that the device is reading something and then displaying, or putting out, that information for you to see.

The term can also mean a summary or report of what happened. After an important meeting, a government official might give reporters a readout of what was discussed. In this sense, it's like getting key information extracted and presented clearly, just as a medical device extracts data and presents it on a screen.