solid

American  

[sol-id] / ˈsɒl ɪd /

adjective

solider, solidest

1. having three dimensions (length, breadth, and thickness), as a geometrical body or figure.

   Synonyms:

   cubic

   Antonyms:

   flat

2. of or relating to bodies or figures of three dimensions.

3. having the interior completely filled up, free from cavities, or not hollow.

   a solid piece of chocolate.

4. without openings or breaks.

   a solid wall.

5. firm, hard, or compact in substance.

   solid ground.

   Synonyms:

   dense

6. having relative firmness, coherence of particles, or persistence of form, as matter that is not liquid or gaseous.

   solid particles suspended in a liquid.

   Synonyms:

   firm, cohesive

   Antonyms:

   loose

7. pertaining to such matter.

   Water in a solid state is ice.

8. dense, thick, or heavy in nature or appearance.

   solid masses of cloud.

9. not flimsy, slight, or light, as buildings, furniture, fabrics, or food; substantial.

   Synonyms:

   sound

10. of a substantial character; not superficial, trifling, or frivolous.

    a solid work of scientific scholarship.

11. without separation or division; continuous.

    a solid row of buildings.

    Synonyms:

    unbroken

    Antonyms:

    divided

12. whole or entire.

    one solid hour.

13. forming the whole; consisting entirely of one substance or material.

    solid gold.

14. uniform in tone or shades, as a color.

    a solid blue dress.

15. real or genuine.

    solid comfort.

16. sound or reliable, as reasons or arguments.

    solid facts.

17. sober-minded; fully reliable or sensible.

    a solid citizen.

18. financially sound or strong.

    Our company is solid.

    Synonyms:

    solvent

19. cubic.

    A solid foot contains 1,728 solid inches.

20. written without a hyphen, as a compound word.

21. having the lines not separated by leads, or having few open spaces, as type or printing.

22. thorough, vigorous, great, big, etc. (with emphatic force, often aftergood ).

    a good solid blow.

    Synonyms:

    strong

23. firmly united or consolidated.

    a solid combination.

24. united or unanimous in opinion, policy, etc.

    Antonyms:

    divided

25. on a friendly, favorable, or advantageous footing (often preceded byin ).

    He was in solid with her parents.

26. Slang. excellent, especially musically.

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noun

solids plural

1. a body or object having three dimensions (length, breadth, and thickness).

2. a solid substance or body; a substance exhibiting rigidity.

idioms

1. do (someone) a solid, to help out, be supportive, or do a favor for.

   Do him a solid and second his nomination.

solid British  

/ ˈsɒlɪd, səˈlɪdɪtɪ /

adjective

1. of, concerned with, or being a substance in a physical state in which it resists changes in size and shape Compare liquid gas

2. consisting of matter all through

3. of the same substance all through

   solid rock

4. sound; proved or provable

   solid facts

5. reliable or sensible; upstanding

   a solid citizen

6. firm, strong, compact, or substantial

   a solid table

   solid ground

7. (of a meal or food) substantial

8. (often postpositive) without interruption or respite; continuous

   solid bombardment

9. financially sound or solvent

   a solid institution

10. strongly linked or consolidated

    a solid relationship

11. geometry having or relating to three dimensions

    a solid figure

    solid geometry

12. (of a word composed of two or more other words or elements) written or printed as a single word without a hyphen

13. printing with no space or leads between lines of type

14. unanimously in favour of

15. (of a writer, work, performance, etc) adequate; sensible

16. of or having a single uniform colour or tone

17. informal excessive; unreasonably strict

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noun

1. geometry

   1. a closed surface in three-dimensional space

   2. such a surface together with the volume enclosed by it

2. a solid substance, such as wood, iron, or diamond

3. (plural) solid food, as opposed to liquid

solid Scientific  

/ sŏl′ĭd /

1. Physics One of four main states of matter, in which the molecules vibrate about fixed positions and cannot migrate to other positions in the substance. Unlike a gas or liquid, a solid has a fixed shape, and unlike a gas, a solid has a fixed volume. In most solids (with exceptions such as glass), the molecules are arranged in crystal lattices of various sizes.

2. Mathematics A geometric figure that has three dimensions.

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solid Cultural  

1. A phase of matter characterized by the tight locking of atoms into rigid structures that resist deforming by outside forces.

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Synonym Usage

See firm ¹.

Other Word Forms

Derived Forms

• solidity
  noun
• solidness
  noun
• subsolid
  noun
• unsolidness
  noun
• half-solid
  adjective
• nonsolid
  adjective
• transsolid
  adjective
• unsolid
  adjective
• nonsolidly
  adverb
• solidly
  adverb
• unsolidly
  adverb

Inflected Forms

Nouns

• solids
  plural

Etymology

Origin of solid

First recorded in 1350–1400; Middle English solide, from Old French solide, from Latin solidus “dense, compact”

Explanation

A solid, as opposed to a liquid or gas, has a size and shape to it. It doesn't flow like water or disappear into the air. At first glance, solid appears to be a simple word, but it really offers shades of meaning. A solid friend is dependable. If you give a solid performance, it was very good, though not quite great. Likewise, if you achieve a solid win, you win by a large, but not huge, majority. In a less figurative use, if a piece of chocolate is solid — as opposed to hollow — it is chocolate throughout.

Example Sentences

See Examples For:

solid solids solider solidest

“From a macro perspective, the combination of easy financial conditions, solid economic growth, healthy CEO confidence, and a friendly regulatory backdrop should support continued M&A activity,” they say.

From MarketWatch ● Jul. 20, 2026

As the new 40-year debt will likely offer a much higher yield than other government securities, it will probably attract solid investor demand.

From The Wall Street Journal ● Jul. 17, 2026

"It's made of very solid material and it's very difficult to establish new technologies because lots of people have been there for decades and they are don't share his vision of digitalisation."

From BBC ● Jul. 17, 2026

ING’s economics team noted that policymakers have sought to maintain ample liquidity and sees a solid chance of a rate cut within the quarter.

From The Wall Street Journal ● Jul. 17, 2026

She couldn’t wait to feel solid ground beneath her feet again.

From "The Wild Robot Escapes" by Peter Brown

After college, he tried going West and struck gold with mining equipment that helped separate solids from slurry.

From The Wall Street Journal ● Jul. 4, 2026

Magnons are tiny waves of magnetization that move through magnetic solids.

From Science Daily ● Jul. 2, 2026

Missing the 20% minimum threshold for cocoa solids in a bar, Nestle had to change the labeling, according to a spokesperson.

From The Wall Street Journal ● Apr. 17, 2026

They also measure the total dissolved solids, which is the combined contents of all organic and inorganic substances, such as minerals, in water.

From BBC ● Feb. 10, 2026

Aristotelians also held that solids are denser and heavier than liquids.

From "The Invention of Science" by David Wootton

I've come to an industrial space in a tech-heavy area of San Francisco expecting to see a menacing humanoid robot solider doing something combat-like: the future of land-based warfare, perhaps.

From BBC ● Jun. 8, 2026

There’s a scene in the 1981 Bill Murray film Stripes where a solider introduces himself to his colleagues as “Psycho,” though his real name is Francis.

From Slate ● Apr. 13, 2026

It was not clear whether the solider who died was among that toll.

From Barron's ● Mar. 12, 2026

Packaged in cosplay costumes — cowgirl, solider, even firefighter and pilot — we were supposed to see her as strong.

From Los Angeles Times ● Mar. 6, 2026

It was over the Battles of Lexington and Concord, and I’d gone in disguised as a British solider.

From "Glitch" by Laura Martin

John Martin, in The New York Times, hailed it as an unlikely success, “the solidest foundation that has yet been laid for the development of the art of ballet in America.”

From New York Times ● Jul. 29, 2021

They persisted in seeing it as the solidest, most plausible candidate.

From The Guardian ● Feb. 28, 2011

The value of the Swiss franc, the world's solidest currency, has increased 5% since last September, while the West German mark has risen 3%.

From Time Magazine Archive

What gave the British their solidest satisfaction was a ruling of the Fund governors on the meaning of "fundamental disequilibrium," a gobbledygook economic cruncher imbedded deep in the Bretton Woods charter.

From Time Magazine Archive

His perception of reality was of the solidest.

From Promenades of an Impressionist by Huneker, James

Related Words

• decent
• genuine
• good
• real
• satisfactory
• satisfying
• serious