variable

adjective: something that is likely to vary or change; not consistent or stable
- The temperature in the desert is highly variable.
noun: in programming, a named storage location that can hold different values during the execution of a program
- The variable x stores the user's input and changes throughout the program.
noun: a symbol that represents an unknown or changeable quantity in mathematics, statistics, or science
- In the equation y = 2x + 3, x is the variable that determines the value of y.
noun: a factor or element that can change or be changed in a situation or experiment
- In our experiment, the temperature was the only variable we altered.