sky

The word “sky” means the space above the earth where clouds, the sun, and stars appear. In plain terms, the open space above us, filled with clouds and stars — or, in sports slang, to send a ball flying way too high.

“Sky” is pronounced skeye (/skaɪ/ in IPA).

Here is “sky” used in a sentence: “The sky turned orange as the sun went down.”

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

The word “sky” comes from Old Norse. From Old Norse ský ("cloud"), which gradually replaced the older English word heofon in everyday use — heofon survives today as "heaven".

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

“Sky” has 2 distinct senses listed in this dictionary. The most common is: the space above the earth where clouds, the sun, and stars appear.

The sky looks blue because gas molecules in the air scatter sunlight, and blue light — which travels in shorter, smaller waves — scatters much more strongly than other colours. This scattered blue light reaches your eyes from every part of the sky, so the daytime sky appears blue overhead.

The sky is the space above the earth as seen from the ground, including the atmosphere where clouds, weather, and birds appear. Space is the vast, near-empty region beyond that atmosphere. The sky does not stop sharply but fades into outer space as the air gradually thins with height.

At sunset the sun sits low, so its light travels through far more atmosphere to reach you. The shorter blue wavelengths scatter away along the way, leaving the longer red and orange wavelengths to come through. That is why sunrises and sunsets glow with warm colour.