Origin: OE. Skie a cloud, Icel. Sk; akin to Sw. & Dan. Sky; cf. AS. Sca, scwa, shadow, Icel. Skuggi; probably from the same root as E. Scum. See Scum, and cf. Hide skin, Obscure.
2. Hence, a shadow. She passeth as it were a sky. (Gower)
Sky is often used adjectively or in the formation of self-explaining compounds; as, sky colour, skylight, sky-aspiring, sky-born, sky-pointing, sky-roofed, etc. Sky blue, an azure colour. Sky scraper, a skysail of a triangular form. Under open sky, out of doors. Under open sky adored. .