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, especially when cut and polished, valued as a precious gem.
a ring or other piece of jewelry containing such a precious stone, especially 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, especially 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.
(used with a singular or plural verb) diamonds, 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 4½-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.
Neil, born 1941, U.S. singer and songwriter.
Cape, a hill in Canada, in S Quebec, on the St. Lawrence River.
a colourless exceptionally hard mineral (but often tinted yellow, orange, blue, brown, or black by impurities), found in certain igneous rocks (esp the kimberlites of South Africa). It is used as a gemstone, as an abrasive, and on the working edges of cutting tools. Composition: carbon. Formula: C. Crystal structure: cubic
( as modifier )
a diamond ring
geometry
a figure having four sides of equal length forming two acute angles and two obtuse angles; rhombus
(modifier) rhombic
a red lozenge-shaped symbol on a playing card
a card with one or more of these symbols or ( when plural ) the suit of cards so marked
baseball
the whole playing field
the square formed by the four bases
(formerly) a size of printer's type approximately equal to 4 1/ 2 point
a figurative name for coal
an unpolished diamond
a person of fine character who lacks refinement and polish
What does diamond mean? A diamond is a clear gemstone known for its use in jewelry and its high price. The word diamond can also refer to the material, which is one of the hardest known substances. It has many practical and industrial applications, including for grinding and polishing—many drill bits have diamond tips, for example. Diamonds are perhaps the most popular gemstone used in jewelry. They are classified as precious gems, meaning that they have a high commercial value. They are often rated based on four main qualities: cut, color, clarity, and carat weight. Many cut diamonds are crystal clear, but sometimes they come in other transparent colors, including pink, yellow, and blue (like the famous Hope diamond). Some diamonds are synthetic—they’re manufactured in laboratories. The diamond is the traditional birthstone for the month of April. It’s associated with the zodiac signs Aries and Taurus. The word diamond is also used to refer to a shape (♦), like the one that’s used as one of the four “suits” on playing cards. Sometimes, it refers to a shape that looks like a cut diamond gem. This is how the word is used in baseball diamond. Diamond can be used as an adjective to describe things that include diamonds (as in a diamond necklace), are made of diamond (as in a diamond drill bit tip), or are diamond-shaped or diamond-patterned, among other things. The word diamond is sometimes used to describe a 75-year anniversary, as in It’s my grandparents’ diamond anniversary this year—I can’t believe they’ve been married for 75 years!Example: Look at her ring—that must be the biggest diamond I’ve ever seen!
1275–1325; Middle English diamant < Old French < Vulgar Latin *diamant-, stem of *diamas, perhaps alteration of *adimas (> French aimant magnet, Old Provençal aziman diamond, magnet), for Latin adamas adamant, diamond
A diamond is a valuable gemstone that's often used to make expensive jewelry. You might admire your friend's diamond earrings, but secretly wonder if they're real. An engagement ring is typically set with one or more diamonds. Diamonds used for jewelry are cut and polished, and they're evaluated for quality and price by weight, or carat, as well as by their cut, clarity, and color. Another kind of diamond is the geometrical shape, which is also seen on playing cards called diamonds, and echoed in the shape of a baseball field, also known as a diamond.
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The qubits were arranged in square, cubic, or diamond shaped lattices.
From Science Daily ● Jul. 20, 2026
The Venetia mine, in the far north of South Africa, accounts for more than 40% of the country's diamond production and employs more than 4,000 people.
From BBC ● Jul. 14, 2026
Announcing its decision to close the Venetia mine, De Beers said it needed to cut costs and streamline operations given the depressed state of the world diamond market.
From BBC ● Jul. 14, 2026
De Beers is majority-owned by British mining giant Anglo American, which is seeking to offload its stake as the natural diamond market faces intense pressure from laboratory-grown gems.
From Barron's ● Jul. 13, 2026
When I offered to help, she raised an eyebrow—she had no idea I could sew—but handed me a coat, a diamond choker, a seam ripper, and a needle.
From "Not Nothing" by Gayle Forman
It is set to start gathering data in five years, and by failing to back Jodrell Bank, the UK risks missing out on this scientific bonanza, according to Prof Philip Diamond.
From BBC ● Jul. 28, 2026
"That didn't work as a narrative because it was too pessimistic," Diamond told AFP.
From Barron's ● Jul. 26, 2026
He chose a meet on the professional Diamond League circuit, at London’s Olympic stadium.
From The Wall Street Journal ● Jul. 22, 2026
He described Diamond Hill’s “workmanlike mentality to investing,” which includes forecasting companies’ fundamental performance at least five years out, supported by “a qualitative assessment of companies we want to own.”
From MarketWatch ● Jul. 15, 2026
Back then, Michael thought that Neil Diamond was terrible and he suspected Gibby did too, but after a few trips, the music morphed into something else—an inside joke.
From "The First State of Being" by Erin Entrada Kelly
"We recognise the protracted challenging conditions as the diamond industry evolves, though we are encouraged by signs of consumer demand growth in the US and beyond, particularly in higher quality diamonds," he said.
From Barron's ● Jul. 13, 2026
A stunning jeweled dagger hilt and scabbard from Jahangir’s reign incorporate more than 2,000 diamonds, rubies and emeralds set in an intricate pattern in gold.
From The Wall Street Journal ● Jul. 11, 2026
Alex Proie in Pennsylvania picked up her ring, made from the gold and diamonds in her five-year anniversary band, a couple of weeks ago and is still wrestling with a mix of feelings.
From BBC ● Jul. 6, 2026
Lower-level employees might get cubic zirconia instead of diamonds.
From Los Angeles Times ● Jun. 12, 2026
The grey sand turned yellow and twinkled as if it was strewn with diamonds.
From "The Horse and His Boy" by C.S. Lewis
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
