1. (a.) Glassy; resembling glass; consisting of glass; transparent, like crystal.

2. (n.) A poetic term for the sea or the atmosphere.

3. (n.) The pellucid substance, present in cells in process of development, from which, according to some embryologists, the cell nucleus originates.

4. (n.) The main constituent of the walls of hydatid cysts; a nitrogenous body, which, by decomposition, yields a dextrogyrate sugar, susceptible of alcoholic fermentation.

Caelus air azure blue sky caelum canopy canopy of heaven cerulean clear as glass cope empyrean ether firmament glass glasslike glassy heaven heavens hyalescent lift lifts sky starry heaven the blue the blue serene vault vault of heaven vitreous vitriform welkin