What does "sky" mean?

Additional senses

1. 2.The apparent arch, or vault, of heaven, which in a clear day is of a blue color; the heavens; the firmament; -- sometimes in the plural. The Norweyan banners flout the sky. Shak.
2. 3.The wheather; the climate. Thou wert better in thy grave than to answer with thy uncovered body this extremity of the skies. Shak. Note: Sky is often used adjectively or in the formation of self- explaining compounds; as, sky color, skylight, sky-aspiring, sky- born, sky-pointing, sky-roofed, etc. Sky blue, an azure color. -- Sky scraper (Naut.), a skysail of a triangular form. Totten. -- Under open sky, out of doors. "Under open sky adored." Milton.
3. 4.To hang (a picture on exhibition) near the top of a wall, where it can not be well seen. [Colloq.] Brother Academicians who skied his pictures. The Century.
4. 5.To throw towards the sky; as, to sky a ball at cricket. [Colloq.]