a. - Sky-blue; resembling the clear blue color of the unclouded sky; cerulean; also, cloudless.
n. - The lapis lazuli.
n. - The clear blue color of the sky; also, a pigment or dye of this color.
n. - The blue vault above; the unclouded sky.
n. - A blue color, represented in engraving by horizontal parallel lines.
v. t. - To color blue.