Definition of diamond

• n. - A precious stone or gem excelling in brilliancy and beautiful play of prismatic colors, and remarkable for extreme hardness.
• n. - A geometrical figure, consisting of four equal straight lines, and having two of the interior angles acute and two obtuse; a rhombus; a lozenge.
• n. - One of a suit of playing cards, stamped with the figure of a diamond.
• n. - A pointed projection, like a four-sided pyramid, used for ornament in lines or groups.
• n. - The infield; the square space, 90 feet on a side, having the bases at its angles.
• n. - The smallest kind of type in English printing, except that called brilliant, which is seldom seen.
• a. - Resembling a diamond; made of, or abounding in, diamonds; as, a diamond chain; a diamond field.