n. Adamant; steel, or some imaginary substance of extreme hardness or impenetrability.n. A precious stone, distinguished from all others by being combustible and by its extreme hardness, as well as by its superior refractive and dispersive power.n. A geometrical figure bounded by four equal straight lines forming two acute and two obtuse angles; a rhomb; a lozenge; specifically, such a figure printed in red on a playing-card.n. A playing-card stamped with one or more red lozenge-shaped figures.n. A tool armed with a diamond, used for cutting glass.n. In base-ball, the square space inclosed within the four bases.n. In heraldry, the tincture black in blazoning by means of precious stones.n. The smallest size of printing-type in common use; a size smaller than pearl. Brilliant, very rarely used, is the only regular size below it.n. This line is printed in diamond.n. Mineral coal, as consisting, like diamonds, of carbon.Resembling a diamond; consisting of diamonds; set with a diamond or diamonds: as, a diamond luster; a diamond necklace; a diamond ring.Lozenge-shaped; rhombic: as, diamond window-panes.Having rhomboid figures or markings: as, the diamond rattlesnake.To set or decorate with diamonds.n.