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• constant
  constant

  adjective

  not changing or varying; uniform; regular; invariable.
• Constant
  Constant

  noun

  Paul Henri Benjamin Balluat Paul d'Estournelles de Constant.

constant

¹ American  

[kon-stuhnt] / ˈkɒn stənt /

adjective

1. not changing or varying; uniform; regular; invariable.

   All conditions during the three experiments were constant.

   Synonyms:

   permanent, immutable

   Antonyms:

   changeable

2. continuing without pause or letup; unceasing.

   constant noise.

   Synonyms:

   unremitting, perpetual

   Antonyms:

   fitful

3. regularly recurrent; continual; persistent.

   He found it impossible to work with constant interruption.

   Synonyms:

   ceaseless, incessant

   Antonyms:

   sporadic

4. faithful; unswerving in love, devotion, etc..

   a constant lover.

   Synonyms:

   true, staunch, loyal

   Antonyms:

   unreliable

5. steadfast; firm in mind or purpose; resolute.

   Synonyms:

   steady

6. Obsolete. certain; confident.

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noun

• constants
  plural

1. something that does not or cannot change or vary.

2. Physics. a number expressing a property, quantity, or relation that remains unchanged under specified conditions.

3. Mathematics. a quantity assumed to be unchanged throughout a given discussion.

Constant ² American  

[kawn-stahn] / kɔ̃ˈstɑ̃ /

noun

1. Paul Henri Benjamin Balluat Paul d'Estournelles de Constant.

2. Jean Joseph Benjamin 1845–1902, French painter.

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Constant ¹ British  

/ kɔ̃stɑ̃ /

noun

1. Benjamin (bɛ̃ʒamɛ̃). real name Henri Benjamin Constant de Rebecque. 1767–1830, French writer and politician: author of the psychological novel Adolphe (1816)

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constant ² British  

/ ˈkɒnstənt /

adjective

1. fixed and invariable; unchanging

2. continual or continuous; incessant

   constant interruptions

3. resolute in mind, purpose, or affection; loyal

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noun

1. something that is permanent or unchanging

2. a specific quantity that is always invariable

   the velocity of light is a constant

3. 1. maths a symbol representing an unspecified number that remains invariable throughout a particular series of operations

   2. physics a theoretical or experimental quantity or property that is considered invariable throughout a particular series of calculations or experiments

4. See logical constant

constant Scientific  

/ kŏn′stənt /

1. A quantity that is unknown but assumed to have a fixed value in a specified mathematical context.

2. A theoretical or experimental quantity, condition, or factor that does not vary in specified circumstances. Avogadro's number and Planck's constant are examples of constants.

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constant Cultural  

1. A number that appears in equations and formulas and does not vary or change. Examples are Planck's constant and the speed of light.

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Synonym Usage

See faithful.

Other Word Forms

Derived Forms

• nonconstant
  noun
• overconstantness
  noun
• overconstant
  adjective
• quasi-constant
  adjective
• unconstant
  adjective
• constantly
  adverb

Inflected Forms

Nouns

• constants
  plural

Etymology

Origin of constant

First recorded in 1350–1400; Middle English, from Latin constant- (stem of constāns, present participle of constāre “to stand firm”), equivalent to con- con- + stā- stand + -nt- present participle suffix

Explanation

Think of something or someone that does not change as constant. A classmate's constant drumming on the table with his fingers could be a constant source of annoyance. Constant derives from Latin verb meaning "to stand with," so something constant is continually standing with you and not wavering. You may be thankful for the constant companionship of your dog but not necessarily for your teacher's constant homework assignments. In math and science, a constant is a number that is fixed and known, unlike a variable which changes with the context. That idea crosses over to real life. If a friend is a constant in your life, that means they have always been with you and there for you.

Example Sentences

See Examples For:

constant Constant constants

With mounting Russian attacks on the capital, his family is in "constant stress" and he tries to distract himself by planting tomatoes.

From Barron's ● Sep. 26, 2026

Steer clear of constant checking and tracking or intervening These may soothe you in the short term, but can inadvertently communicate to your young adult: "I am not sure you can cope without me."

From BBC ● Sep. 25, 2026

But under the constant watch of phone cameras and gossip that travels at the speed of social media feeds, they face greater pressures.

From Salon ● Sep. 24, 2026

“It was always a constant answer of no,” he recalled.

From MarketWatch ● Sep. 24, 2026

Like there was a constant “Shhhhhh” hushing us all the time, in every room.

From "Ida B" by Katherine Hannigan

Constant shifts in diesel prices, transportation costs and the tariff environment have emboldened business to feel justified in passing costs on to consumers, said Firrincieli, the sales manager from the logistics company.

From The Wall Street Journal ● Sep. 26, 2026

Constant stirring helps remove air bubbles, resulting in completely transparent ice, known as "junpyo" in Japanese.

From Barron's ● Sep. 6, 2026

"Constant never-ending legal wranglings that undermine the contract between a nation and those that serve is neither a good use of taxpaying money nor an effective execution of strategy."

From BBC ● Jun. 16, 2026

Constant stretching and compression of a moon can create recurring wet dry cycles where water repeatedly evaporates and condenses.

From Science Daily ● May 29, 2026

“In the meantime . . . constant vigilance, Potter. Constant vigilance.”

From "Harry Potter And The Goblet Of Fire" by J. K. Rowling

Despite generations of increasingly sophisticated experiments, the gravitational constant remains less precisely known than comparable constants associated with nature's other three fundamental forces: electromagnetism and the strong and weak nuclear forces.

From Science Daily ● Sep. 20, 2026

Those measurements could improve scientists' understanding of the muon's mass and fundamental physical constants, another long-term goal of the research group.

From Science Daily ● Sep. 18, 2026

Phone-induced distractedness, flusteredness, and agitation had been constants in life before prison.

From The Wall Street Journal ● Aug. 5, 2026

Their work suggests that the Universe's fundamental constants sit within an extremely narrow range that allows liquids to flow in ways living cells depend on.

From Science Daily ● May 8, 2026

Through most of his moves, Door had been one of the few constants in his life.

From "Boy 2.0" by Tracey Baptiste

Related Words

• ceaseless
• chronic
• continual
• continuous
• endless
• eternal
• incessant
• nonstop
• perpetual
• persistent
• relentless
• sustained
• unending
• uninterrupted
• unrelenting
• unremitting