variable
adjective
1a : able or apt to vary : subject to variation or changes variable winds variable costs
1b : 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
noun
1a : a quantity that may assume any one of a set of values
1b : a symbol representing a variable
2a : something that is variable
2b : a factor in a scientific experiment that may be subject to change
3 : variable star
First Known Use of variable
Adjective
14th century, in the meaning defined at sense 1a
Noun
1816, in the meaning defined at sense 1a
History and Etymology for variable
Adjective
Middle English, borrowed from Anglo-French, borrowed from Late Latin variābilis "changeable," from Latin variāre "to make changeable, vary" + -ābilis -able