Source : Webster's Revised Unabridged Dictionary (1913)

Sky \Sky\ (sk[imac]), n.; pl. {Skies} (sk[imac]z). [OE. skie a
   cloud, Icel. sk[=y]; akin to Sw. & Dan. sky; cf. AS. sc[=u]a,
   sc[=u]wa, shadow, Icel. skuggi; probably from the same root
   as E. scum. [root]158. See {Scum}, and cf. {Hide} skin,
   {Obscure}.]
   1. A cloud. [Obs.]

            [A wind] that blew so hideously and high, That it ne
            lefte not a sky In all the welkin long and broad.
                                                  --Chaucer.

   2. Hence, a shadow. [Obs.]

            She passeth as it were a sky.         --Gower.

   3. 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.

   4. 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.