diamond

1 of 3

noun

di·​a·​mond ˈdī-(ə-)mənd 

often attributive

1

a

: native crystalline carbon that is the hardest known mineral, that is usually nearly colorless, that when transparent and free from flaws is highly valued as a precious stone, and that is used industrially especially as an abrasive

also : a piece of this substance

b

: crystallized carbon produced artificially

2

: something that resembles a diamond (as in brilliance, value, or fine quality)

3

: a square or rhombus-shaped figure usually oriented with the long diagonal vertical

4

a

: a playing card marked with a stylized figure of a red diamond

b

diamonds plural in form but singular or plural in construction : the suit comprising cards marked with diamonds

5

: a baseball infield

also : the entire playing field

diamond

2 of 3

verb

diamonded; diamonding; diamonds

transitive verb

: to adorn with or as if with diamonds

diamond

3 of 3

adjective

: of, relating to, or being a 60th or 75th anniversary or its celebration

diamond jubilee

Examples of diamond in a Sentence

Noun

a necklace studded with diamonds and rubies

The ruby was surrounded by a ring of diamond.

The children cut the fabric into diamonds.

one heart, two diamonds, and two clubs

He played the queen of diamonds.

Adjective

the celebration of Queen Victoria's diamond jubilee in 1897

Recent Examples on the Web

Noun

Similar moves have been made in the past by De Beers, which has long seen itself as the custodian of the diamond industry. —Tim Treadgold, Forbes, 26 Dec. 2024

Always punctuating his looks are the wide receiver's signature hefty diamond chains. —Christian Allaire, Vogue, 26 Dec. 2024

Verb

The material is a synthetic form of aluminum oxide, one of the hardest substances second only to diamond. —Paige Reddinger, Robb Report, 19 Dec. 2024

Mali has other natural resources that Moroccan industries could eye for extraction, such as gold, uranium, iron ore, and possibly diamonds. FROM FEZ TO TIMBUKTU Only time will tell whether Morocco’s relationship with Mali will be that of an equal partner or a satellite. —Vish Sakthivel, Foreign Affairs, 14 Jan. 2014

Adjective

Barry Chin/Globe Staff When Oneil Cruz followed with a grounder to first, first baseman Triston Casas eschewed the sure out and instead elected to make a cross-diamond throw in hopes of getting the lead runner. —Alex Speier, BostonGlobe.com, 5 Apr. 2023

The second most popular non-diamond gemstone? —Nicole Kliest, refinery29.com, 10 Mar. 2022

Word History

Etymology

Noun

Middle English diamaunde, from Middle French diamand, from Late Latin diamant-, diamas, alteration of Latin adamant-, adamas hardest metal, diamond, from Greek

First Known Use

Noun

14th century, in the meaning defined at sense 1a

Verb

1751, in the meaning defined above

Adjective

1872, in the meaning defined above

Phrases Containing diamond

• black diamond
• diamond in the rough
• rough diamond

Kids Definition

diamond

noun

di·​a·​mond

ˈdī-(ə-)mənd

1

a

: a very hard stone of crystallized carbon that is used as a precious gem and industrially as a powder for grinding, smoothing, or polishing and in cutting tools

b

: a piece of this stone especially when cut and polished

2

: a shape that is formed by four equal straight lines and has two opposite acute angles and two opposite obtuse angles

3

a

: a playing card marked with a red diamond-shaped figure

b

plural : the suit made up of cards marked with diamonds

4

a

: infield sense 1a

b

: the entire playing field in baseball or softball

Etymology

Noun

Middle English diamaunde "diamond," from early French diamant (same meaning), derived from Latin diamant-, diamas, an altered form of adimant-, adimas and adamant-, adamas "the hardest metal, diamond," from Greek adamant-, adamas (same meaning) — related to adamant

Word Origin

Diamond, the hardest substance found in nature, was known to the ancient Greeks. They called the gemstone adamas, using the same word they used for any unbreakable or indestructible substance, such as the hardest metal, or for anything unmovable. The stem of this word was adamant-. Later, Latin writers borrowed these Greek words, sometimes as adamant-, adamas and sometimes adimant-, adimas. The forms adamant-, adamas in time gave us the English noun adamant, meaning "an imaginary stone of great hardness," and the adjective adamant, meaning "firmly fixed or decided." The "i" forms in Latin were later changed from adimant-, adimas to diamant-, diamas and came to be used only for the gemstone which we now call diamond.

Biographical Definition

Diamond

biographical name

Di·​a·​mond ˈdī-(ə-)mənd 

Peter A(rthur) 1940–     American economist