diamond

Diamond is a very hard mineral made from carbon that is shiny like glass.

Example: The blades of cutting tools like saws and knives are sometimes coated in diamond.

A diamond is a precious gemstone made from the mineral diamond.

Example: The diamond is the birthstone of April.

In geometry, a diamond (◆) is a rhombus that is a square tilted at a 45-degree angle.

In card games, the diamonds are one of the four playing card suits.

Example: The diamonds and the hearts are the two red-colored suits.

In cards games, a diamond is a card of the diamond suit.

Example: I have three diamonds in my hand.