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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

"My TV fell on me, my mirror smashed and the roads around me were damaged," she told the BBC – adding that she had started preparing evacuation bags amid the "constant aftershocks".

From BBC ● Jul. 29, 2026

Air Liquide backed its outlook for the year, remaining confident in its ability to increase its operating margin by 1 percentage point and deliver recurring net profit growth at constant exchange rates.

From The Wall Street Journal ● Jul. 28, 2026

After all, his previous four seasons spent coaching the Trojans had been nothing short of a powder keg, filled with ups and downs, as well as a constant undercurrent of tension and uncertainty.

From Los Angeles Times ● Jul. 28, 2026

He was worn out from not being able to sleep due to the "constant noise."

From Barron's ● Jul. 25, 2026

“If all variables are constant with every repeated scenario, is it ever possible to have a different outcome?”

From "Sir Fig Newton and the Science of Persistence" by Sonja Thomas

Constant queues of visitors wanted to see the latest advances in the robotics field.

From BBC ● Jun. 17, 2026

Constant improvements in semiconductor technology could see other new classes of chips rise up and take their place, OneChronos CEO Kelly Littlepage said in comments shared with MarketWatch.

From MarketWatch ● May 12, 2026

Social media has created the conditions for this “doomer mindset” to flourish: Constant exposure to information, algorithm-driven echo chambers, and excessive screen time distort perception and isolate teens, making it harder to discern what’s true.

From Slate ● May 12, 2026

Constant upkeep and repair can be a kind of life-affirming ritual—an appreciation for how even the best-made machines require the regular intercession of human skill and diligence.

From The Wall Street Journal ● Dec. 5, 2025

Constant, and well directed Patrols, seem indespensibly necessary.

From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume II: The Kingdom on the Waves" by M.T. Anderson

Most other fundamental constants are known to six or more significant digits with far greater agreement.

From Science Daily ● May 18, 2026

For decades, the mystery of fundamental constants was mostly explored through black holes, stars, and subatomic particles.

From Science Daily ● May 8, 2026

The idea remains highly theoretical, and many physicists would caution that there is still no accepted explanation for why the constants of nature have their observed values.

From Science Daily ● May 8, 2026

Spurs' 5-3-2 shape lacks coverage in the wide areas with the wing-backs the only constants here.

From BBC ● Mar. 12, 2026

Most of the stylists are familiar, constants in the everchanging pool of tributes.

From "The Hunger Games" by Suzanne Collins

Related Words

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