a pure or nearly pure, extremely hard form of carbon, naturally crystallized in the isometric system.

a piece of this stone.

a transparent, flawless or almost flawless piece of this stone, esp. when cut and polished, valued as a precious gem.

a ring or other piece of jewelry containing such a precious stone, esp. an engagement ring.

a piece of this stone used in a drill or cutting tool.

a tool provided with such an uncut stone, used for cutting glass.

crystallized carbon, or a piece of it, artificially produced.

an equilateral quadrilateral, esp. as placed with its diagonals vertical and horizontal; a lozenge or rhombus.

any rhombus-shaped figure or object oriented with its diagonals vertical and horizontal.

a red rhombus-shaped figure on a playing card.

a card of the suit bearing such figures.

diamonds, ( used with a singular or plural verb ) the suit so marked

Diamonds is trump. Diamonds are trump.

Baseball .

the space enclosed by home plate and the three bases; infield.

the entire playing field.

Printing . a 4 1 / 2 -point type of a size between brilliant and pearl.

made of or set with a diamond or diamonds.

having the shape of a diamond

a dress with a diamond print.

indicating the 75th, or sometimes the 60th, event of a series, as a wedding anniversary.

to adorn with or as if with diamonds. ?

diamond in the rough

a person of fine character but lacking refined manners or graces.

adjective

adamantine , diamondiferous

noun

allotrope , bort , brilliant , corundum , gem , gemstone , ice , jager , jewel , lozenge , paragon , rhinestone , rhombus , rock , solitaire , zircon