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

The company recently postponed a planned spinoff of its prized missile business that makes solid rocket motors—a key component of interceptors—to at least mid-2027, citing unfavorable market conditions.

From The Wall Street Journal ● Aug. 28, 2026

For now, the National Weather Service is forecasting a “mostly cloudy” night, meaning that even geographical front-row seats to the celestial phenomenon won’t guarantee a solid viewing.

From Los Angeles Times ● Aug. 26, 2026

Verizon, Altria and United Parcel Service are among the companies with dividend yields that match or beat bonds and also boast solid earnings prospects.

From Barron's ● Aug. 26, 2026

Their approach transforms natural killer cells, a type of immune cell known for rapidly attacking abnormal cells, into a specialized tissue resident form that can move into solid tumors and destroy cancer cells.

From Science Daily ● Aug. 25, 2026

She had frozen solid, on her feet, exactly as if she were alive—perfectly still and upright.

From "Woodsong" by Gary Paulsen

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

"In solids, molecules are packed tightly, and the π electron clouds -- regions of high electron density hovering above and below each molecular plane -- can overlap," says Sasaki.

From Science Daily ● Jun. 26, 2026

In solids, atoms form tightly packed lattice structures.

From Science Daily ● Apr. 19, 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

"She won’t eat anything else. She stopped eating solids after she turned one hundred. That was, let’s see, three years ago."

From "Interpreter of Maladies" by Jhumpa Lahiri

The Mail on Sunday follows with a photo of a Spanish solider checking on two migrants collapsed on the beach in Ceuta.

From BBC ● Aug. 1, 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

But only about 5% are as potent as the tunes here--whoever inspired it, this is Lovett's solidest package in a long, ornery career.

From Time Magazine Archive

But in Addison Road, a quiet corner of London's fashionable Kensington district where many members of the Russian Embassy staff live in cozy proximity to some of Britain's solidest citizens, the atmosphere was less honeyed.

From Time Magazine Archive

Now Pierre began to see mysteries interpierced with mysteries, and mysteries eluding mysteries; and began to seem to see the mere imaginariness of the so supposed solidest principle of human association.

From Pierre; or The Ambiguities by Herman Melville

Related Words

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