n. A precious stone next in hardness to the diamond, and nearly as valuable when of fine quality: a variety of the mineral corundum.n. The color of the sapphire; blue.n. In heraldry, a tincture, the color blue, in blazoning by means of precious stones. Compare blazon, n., 2.n. In ornithology, a sapphirewing.Resembling sapphire; of a deep brilliant blue.