constant
adjective
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constant
1 American
[kon-stuhnt]
/ ˈkɒn stənt /
adjective
-
not changing or varying; uniform; regular; invariable.
All conditions during the three experiments were constant.
- Antonyms:
- changeable
-
continuing without pause or letup; unceasing.
constant noise.
- Synonyms:
- unremitting, perpetual
- Antonyms:
- fitful
-
regularly recurrent; continual; persistent.
He found it impossible to work with constant interruption.
- Antonyms:
- sporadic
-
faithful; unswerving in love, devotion, etc..
a constant lover.
- Antonyms:
- unreliable
-
steadfast; firm in mind or purpose; resolute.
- Synonyms:
- steady
-
Obsolete. certain; confident.
noun
constants
plural
-
something that does not or cannot change or vary.
-
Physics. a number expressing a property, quantity, or relation that remains unchanged under specified conditions.
-
Mathematics. a quantity assumed to be unchanged throughout a given discussion.
Constant
2
American
[kawn -stahn]
/ kɔ̃ˈstɑ̃ /
noun
-
Paul Henri Benjamin Balluat Paul d'Estournelles de Constant.
-
Jean Joseph Benjamin 1845–1902, French painter.
Constant
1
British
/ kɔ̃stɑ̃ /
noun
constant
2
British
/ ˈkɒnstənt /
adjective
-
fixed and invariable; unchanging
-
continual or continuous; incessant
constant interruptions
-
resolute in mind, purpose, or affection; loyal
noun
-
something that is permanent or unchanging
-
a specific quantity that is always invariable
the velocity of light is a constant
-
-
maths a symbol representing an unspecified number that remains invariable throughout a particular series of operations
-
physics a theoretical or experimental quantity or property that is considered invariable throughout a particular series of calculations or experiments
-
-
See logical constant
constant
Scientific
/ kŏn′stənt /
-
A quantity that is unknown but assumed to have a fixed value in a specified mathematical context.
-
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.
constant
Cultural
Synonym Usage
See faithful.
Other Word Forms
Derived Forms
-
nonconstantnoun
-
overconstantnessnoun
-
overconstantadjective
-
quasi-constantadjective
-
unconstantadjective
-
constantlyadverb
Inflected Forms
Nouns
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.
Vocabulary lists containing constant
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Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
Though that hasn’t stopped audiences and critics from making constant comparisons between “The Exorcist” and “Obsession.”
From Salon ● Jul. 22, 2026
The documentary traces Manson to his troubled childhood and almost constant incarceration in youth facilities and jails.
From Los Angeles Times ● Jul. 22, 2026
Net sales for the second quarter were $14.41 billion, up 1% at constant currency, the Swiss drugmaker said Tuesday.
From The Wall Street Journal ● Jul. 21, 2026
The solar wind is a constant flow of fast-moving charged particles released by the Sun.
From Science Daily ● Jul. 21, 2026
Or djinns he’d surely cheated in a bargain, avenging themselves with a constant itch in his ear.
From "The Many Assassinations of Samir, the Seller of Dreams" by Daniel Nayeri
"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
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
“In the meantime . . . constant vigilance, Potter. Constant vigilance.”
From "Harry Potter And The Goblet Of Fire" by J. K. Rowling
Scientists could observe the optical effects, but they had not directly measured the material's full optical constants.
From Science Daily ● Jun. 1, 2026
The study, published in Science Advances in 2023, builds on earlier work by physicist Kostya Trachenko and colleagues showing that liquid viscosity is tied directly to fundamental physical constants.
From Science Daily ● May 8, 2026
The constants not only appear compatible with a universe full of matter, but also with biological systems that depend on delicate liquid dynamics.
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
The others would come and go, but Cassandra and I were constants.
From "Ugly" by Robert Hoge
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.