sky

noun, plural skies. Often skies (for defs 1–4).

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.