variable

/ˈvɛriəbəl/

/ˈvɛriəbəl/

Other forms: variables

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.

Definitions of variable

1. noun

   something that is likely to vary; something that is subject to variation
   “the weather is one variable to be considered”

   type of:

   thing

   a separate and self-contained entity
2. noun

   a quantity that can assume any of a set of values
   synonyms: variable quantity

   types:

   argument

   a variable in a logical or mathematical expression whose value determines the dependent variable; if f(x)=y, x is the independent variable

   experimental variable, independent variable

   (statistics) a variable whose values are independent of changes in the values of other variables

   correlate, correlative

   either of two or more related or complementary variables

   degree of freedom

   (statistics) an unrestricted variable in a frequency distribution

   dependent variable

   (statistics) a variable in a logical or mathematical expression whose value depends on the independent variable

   predictor variable

   a variable that can be used to predict the value of another variable (as in statistical regression)

   infinitesimal

   (mathematics) a variable that has zero as its limit

   chance variable, random variable, stochastic variable, variant, variate

   a variable quantity that is random

   scalar

   a variable quantity that cannot be resolved into components

   tensor

   a generalization of the concept of a vector

   vector

   a variable quantity that can be resolved into components

   factor

   an independent variable in statistics

   cross product, vector product

   a vector that is the product of two other vectors

   resultant, vector sum

   a vector that is the sum of two or more other vectors

   radius vector

   a line connecting a point in space to the origin of a polar coordinate system

   radius vector

   a line connecting a satellite to the center of the body around which it is rotating

   type of:

   quantity

   the concept that something has a magnitude and can be represented in mathematical expressions by a constant or a variable
3. noun

   a symbol (like x or y) that is used in mathematical or logical expressions to represent a variable quantity
   types:

   placeholder

   a symbol in a logical or mathematical expression that can be replaced by the name of any member of specified set

   unknown, unknown quantity

   a variable whose values are solutions of an equation

   type of:

   symbol

   an arbitrary sign (written or printed) that has acquired a conventional significance
4. noun

   a star that varies noticeably in brightness
   synonyms: variable star

   examples:

   North Star

   the brightest star in Ursa Minor; at the end of the handle of the Little Dipper; the northern axis of the earth points toward it

   type of:

   star

   (astronomy) a celestial body of hot gases that radiates energy derived from thermonuclear reactions in the interior
5. adjective

   marked by diversity or difference
   “nature is infinitely variable”

   synonyms: varying

   varied

   characterized by variety
6. adjective

   liable to or capable of change
   “rainfall in the tropics is notoriously variable”

   “variable winds”

   “variable expenses”

   synonyms:

   inconsistent

   displaying a lack of consistency

   inconstant

   likely to change frequently often without apparent or cogent reason; variable

   changeable, uncertain, unsettled

   subject to change

   covariant

   changing so that interrelations with another variable quantity or set of quantities remain unchanged

   multivariate

   pertaining to any procedure involving two or more variables

   protean

   taking on different forms

   shifting

   continuously varying

   variant

   exhibiting variation and change

   versatile

   changeable or inconstant

   antonyms:

   invariable

   not liable to or capable of change

   consistent

   (sometimes followed by `with') in agreement or consistent or reliable

   constant

   steadfast in purpose or devotion or affection

   changeless, constant, invariant, unvarying

   unvarying in nature

   hard-and-fast, strict

   (of rules) stringently enforced

   invariant

   unaffected by a designated operation or transformation
7. adjective

   (used of a device) designed so that a property (as e.g. light) can be varied
   “a variable capacitor”

   “variable filters in front of the mercury xenon lights”

   synonyms:

   adaptable

   capable of adapting (of becoming or being made suitable) to a particular situation or use