n. A window placed in the roof of a house, or in a ceiling; a frame set with glass, whether horizontal or in one or more inclined planes, and placed in a roof or ceiling, or in some cases, as in photographers' studios, forming a considerable part of the roof, for the purpose of lighting passages or rooms below, or for affording special facilities for lighting, as for artists' or photographers' needs.n. The light of the sky; specifically, the blue or pale white color of the aërial vault.n. Illumination by means of the light of the sky: as, a studio with a good skylight.