variable

The word “variable” means likely to change, or capable of being changed. In plain terms, something variable can change, and a variable (the noun) is a thing — a factor, a quantity, or a piece of stored data — that is allowed to change.

“Variable” is pronounced VEH-uh-ree-uh-bl ([ˈvæɹ.i.ə.bl̩] in IPA).

Here is “variable” used in a sentence: “Mountain weather is famously variable, shifting from sun to snow in an hour.”

Words with a similar meaning to “variable” include capricious, changeful, fickle, fitful, flexible and fluctuating.

Depending on how it is used, “variable” can be an adjective and a noun.

The word “variable” comes from Latin. From Old French variable, from Latin variare, "to change," based on varius, "different, varied.".

“Variable” is a fairly common word in modern English.

“Variable” has 3 distinct senses listed in this dictionary. The most common is: likely to change, or capable of being changed.

A variable is a factor or quantity that can change or take different values. A constant stays the same and does not change. In maths and science, variables shift while constants are fixed throughout a problem.

'Variable' as an adjective means likely to change or capable of being changed. 'Invariable' means the opposite: never changing or fixed. So variable weather keeps shifting, while an invariable routine stays exactly the same.

As a noun, a variable is a factor or quantity that can take different values, often shown by a letter such as x or y. It contrasts with a fixed number, because its value can change within a problem. Solving an equation often means finding the value of the variable.

'Variable' works as both. As an adjective it describes something likely to change, as in 'variable results.' As a noun it names a quantity that can change, as in 'an unknown variable.'