variable

Able to vary or be varied.

variable winds or seasons; a variable quantity; a variable resistor

Likely to vary.

Lest that thy love prove likewise variable.

Marked by diversity or difference.

Having no fixed quantitative value.

Tending to deviate from a normal or recognized type.

Something that is variable.

Something whose value may be dictated or discovered.

There are several variables to consider here.

Bats host many high-profile viruses that can infect humans, including severe acute respiratory syndrome and Ebola. A recent study explored the ecological variables that may contribute to bats’ propensity to harbor such zoonotic diseases by comparing them with another order of common reservoir hosts: rodents.

A quantity that may assume any one of a set of values.

A symbol representing a variable.

A named memory location in which a program can store intermediate results and from which it can read them.