variable

American  

[vair-ee-uh-buhl] / ˈvɛər i ə bəl /

adjective

1. apt or liable to vary or change; changeable: variable moods.

   variable weather;

   variable moods.

   Antonyms:

   constant

2. capable of being varied or changed; alterable.

   a variable time limit for completion of a book.

3. inconstant; fickle.

   a variable lover.

   Synonyms:

   mercurial, unsteady, vacillating

   Antonyms:

   constant

4. having much variation or diversity.

5. Biology. deviating from the usual type, as a species or a specific character.

6. Astronomy. (of a star) changing in brightness.

7. Meteorology. (of wind) tending to change in direction.

8. Mathematics. having the nature or characteristics of a variable.

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noun

• variables
  plural

1. something that may or does vary or change; a variable feature or factor.

2. Mathematics, Computers.

   1. a quantity or function that may assume any given value or set of values.

   2. a symbol that represents this.

3. Logic. (in the functional calculus) a symbol for an unspecified member of a class of things or statements.

4. Astronomy. variable star.

5. Meteorology.

   1. a shifting wind, especially as distinguished from a trade wind.

   2. variables, doldrums.

variable British  

/ ˈvɛərɪəbəl /

adjective

1. liable to or capable of change

   variable weather

2. (of behaviour, opinions, emotions, etc) lacking constancy; fickle

3. maths having a range of possible values

4. (of a species, characteristic, etc) liable to deviate from the established type

5. (of a wind) varying its direction and intensity

6. (of an electrical component or device) designed so that a characteristic property, such as resistance, can be varied

   variable capacitor

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noun

1. something that is subject to variation

2. maths

   1. an expression that can be assigned any of a set of values

   2. a symbol, esp x, y, or z, representing an unspecified member of a class of objects, numbers, etc See also dependent variable independent variable

3. logic a symbol, esp x, y, z, representing any member of a class of entities

4. computing a named unit of storage that can be changed to any of a set of specified values during execution of a program

5. astronomy See variable star

6. a variable wind

7. (plural) a region where variable winds occur

variable Scientific  

/ vâr′ē-ə-bəl /

1. A mathematical quantity capable of assuming any of a set of values, such as x in the expression 3 x + 2.

2. A factor or condition that is subject to change, especially one that is allowed to change in a scientific experiment to test a hypothesis.

3. See more at control

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Usage

What is a variable? In the context of scientific experiments, a variable is any factor that could change or be changed. So, for instance, if you’re measuring how effective a medication is, variables could include the amount of dosage, how frequently it’s taken, and the characteristics of each test subject, such as their age and weight. In general, variables are called variables because they vary. However, in scientific experiments, some variables are kept the same on purpose—such a variable is called a control variable (or sometimes simply just a control). There are three different types of variables: dependent variables, independent variables, and control variables. Independent variables are the factors that you change. Dependent variables are things that are affected by the changes that you make—the results of the tests (which depend on the independent variables). Control variables are the factors that you do not change. They are kept the same for every test or measurement in order to make sure that the results can be compared fairly. For example, let’s say you’re trying to figure out which brand of plant food will help a sunflower grow to the tallest height. The dependent variable is the final height of the sunflower. The independent variable (the factor that you change) is the brand of plant food. There are a number of other factors that could impact the growth of the plant, including things like the amount of sunlight and the amount of water. To allow for a proper comparison of the results, these need to be control variables—they need to be controlled, or kept the same. This way, you can have a greater degree of certainty that the final difference in heights (the dependent variable) is due to which food each sunflower received (the independent variable), not differences in sunlight or water. Properly setting the variables is crucial to scientifically sound experiments and studies.

Other Word Forms

Derived Forms

• nonvariableness
  noun
• unvariableness
  noun
• variability
  noun
• variableness
  noun
• hypervariable
  adjective
• nonvariable
  adjective
• unvariable
  adjective
• hypervariably
  adverb
• nonvariably
  adverb
• unvariably
  adverb
• variably
  adverb

Inflected Forms

Nouns

• variables
  plural

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Etymology

Origin of variable

First recorded in 1350–1400; late Middle English, from Latin variābilis, equivalent to vari(us) “speckled, variegate, diverse” + -ābilis adjective suffix; see various, -able

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Explanation

The adjective variable is used to describe something that is liable to change often, such as the weather, interest rates, or your teacher's mood. If you mention the noun variable to people who are math-phobic, you may give them nightmares because they don't like to think about numbers or values that can change in equations. The adjective form of variable has been around since the late 1300s, applying first to people, and then, in the late 1400s, to weather. The noun form first appeared in Lacroix's Differential and Integral Calculus in 1816, guaranteeing that math students would be solving for the variable x for generations to come.

Example Sentences

See Examples For:

variable variables

Wall Street manias and crashes, sadly, are about as variable as a Scooby-Doo episode.

From MarketWatch ● Oct. 27, 2026

Under scrutiny, some companies, including grocery-ordering service Instacart, have backed away from experiments with variable pricing.

From The Wall Street Journal ● Oct. 26, 2026

But he surely understood that this was an incautiously brief period of measurement, for the river’s annual flow was wildly variable, ranging from about 9.1 million to 25 million acre-feet during the 20-year sampling.

From Los Angeles Times ● Oct. 22, 2026

The two groups of obese animals were fed the same diet throughout the experiment to avoid introducing another variable.

From Science Daily ● Oct. 8, 2026

He went to withdraw money from his savings account, in order to continue his steady assault on all nine hundred and ninety-nine possible permutations of a three-digit variable.

From "Middlesex: A Novel" by Jeffrey Eugenides

Building on their earlier work, they used a self-similar form of Einstein's equations to represent the standard cosmological model as a rest point, a mathematical state in which the system's defining variables remain unchanged.

From Science Daily ● Oct. 29, 2026

“There are just so many variables that the insurance companies didn’t really know how to price it, and so it’s been very expensive for motor carriers to insure these trucks,” Loya said.

From Los Angeles Times ● Oct. 29, 2026

Open-weight models are those whose parameters, or variables learned and adjusted during training, can be downloaded, run or modified by different developers.

From MarketWatch ● Sep. 23, 2026

Meanwhile, the structure of the program drives a set of crucial economic variables.

From The Wall Street Journal ● Sep. 17, 2026

But once you changed any of those variables — the material on the test, or the situation in which it was administered — the kinds of cheating would change as well.

From "The Tipping Point" by Malcolm Gladwell

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Related Words

• fickle
• fluctuating
• volatile

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