- Date: 14th century
- 1 a : able or apt to vary : subject to variation or changes <variable winds> <variable costs>
- b : fickle, inconstant
- 2 : characterized by variations
- 3 : having the characteristics of a variable
- 4 : not true to type : aberrant —used of a biological group or character
A variable (pronounced /ˈvɛəriəbəl/; VAIR-ee-ə-bəl) is a symbol that stands for a value that may vary; the term usually occurs in opposition to constant, which is a symbol for a non-varying value, i.e. completely fixed or fixed in the context of use. The concepts of constants and variables are fundamental to all modern mathematics, science, engineering, and computer programming.