Longman Dictionary of Contemporary English - sky

~ n 1 the space above the earth where clouds and the sun and stars appear  (The rocket shot up into the sky. | The sky turned dark just before the storm. | a patch/strip etc of sky)  (There's a patch of blue sky between the clouds. | a blue/cloudy etc sky (=used to describe how the sky looks at a particular time))  (The sun blazed down from a clear blue sky.) 2 skies a word meaning sky, used especially when describing the weather  (a land of blue skies and warm sunshine | the skies)  (The skies were filled with scudding clouds. | the crowded skies above our major airports) 3 the sky's the limit spoken used to say that there is no limit to what someone can achieve, spend, win etc  (- see also pie in the sky pie (4), praise sb/sth to the skies praise1 (1))