Sky

1. the region of the clouds or the upper air; the upper atmosphere of the earth: airplanes in the sky; cloudy skies.

2. the heavens or firmament, appearing as a great arch or vault.

3. the supernal or celestial heaven: They looked to the sky for help.

4. the climate: the sunny skies of Italy.

5. Obsolete. a cloud.

–verb (used with object)
6. Informal. to raise, throw, or hit aloft or into the air.

7. Informal. to hang (a painting) high on a wall, above the line of vision.

—Verb phrase
8. sky up, Falconry. (of prey, when flushed) to fly straight upward.

—Idioms

9. out of a or the clear sky, without advance notice or warning; abruptly: An old beau phoned her out of a clear sky. Also, out of a or the clear blue sky.

10. to the skies, with lavishness or enthusiasm; extravagantly: to praise someone to the skies. Also, to the sky.