The sun is the star that our planet revolves around. You might enjoy sitting under the sun on a tropical beach — but be sure to put on plenty of sunscreen.
Our sun is more than 100 times larger than the Earth. If it weren't for the sun, the brightest object in our solar system, there would be no life on Earth: the light that the sun provides grows the food we eat and the heat of the sun keeps our environment warm enough to live. The sun is also responsible for the Earth's liquid water, which would be ice without it. As a verb, to sun means "to sit in the sun." The word comes from the Old English sunne.