sun

The word “sun” means the star at the centre of our solar system, which gives Earth light and heat. In plain terms, the star that lights and warms our planet, or the warmth/light it gives off.

“Sun” is pronounced suhn (/sʌn/ in IPA).

Here is “sun” used in a sentence: “The sun rose over the hills just after six.”

Depending on how it is used, “sun” can be a noun and a verb.

The word “sun” comes from Old English. From Old English sunne, from a very old Germanic and Indo-European root shared by "sun" words across most European languages.

“Sun” is a very common word in modern English, usually learned at around the A1 level.

“Sun” has 3 distinct senses listed in this dictionary. The most common is: the star at the centre of our solar system, which gives Earth light and heat.

The sun is a star: a vast ball of hot, glowing gas held together by its own gravity, producing light and heat through nuclear fusion at its core. Planets like Earth are much smaller, cooler bodies that orbit it. The sun only looks different from other stars because it is so close to us.

The sun is made almost entirely of hydrogen and helium in the form of plasma: gas so hot its atoms have broken apart. In its core, immense pressure and heat fuse hydrogen into helium, releasing the energy that reaches Earth as sunlight and warmth. Traces of heavier elements make up the rest.

On average the sun lies about 93 million miles (150 million kilometres) from Earth, a distance known as an astronomical unit. Its light takes roughly eight minutes to reach us. The gap varies slightly through the year because Earth's orbit is not a perfect circle, bringing it a little nearer, then further.

The sun is the source of nearly all energy and life on Earth. Its light and heat drive the climate, weather, and seasons, and power photosynthesis, which feeds plants and, in turn, almost every other living thing. Its gravity also holds the solar system together, keeping Earth in a stable orbit.