来自vary,改变，多变。

variable (adj.)

late 14c., of persons, "apt to change, fickle," from Old French variable "various, changeable, fickle," from Late Latin variabilis "changeable," from variare "to change" (see vary). Of weather, seasons, etc., attested from late 15c.; of stars, from 1788.

variable (n.)

"quantity that can vary in value," 1816, from variable (adj.) in mathematical sense of "quantitatively indeterminate" (1710). Related: Variably; variability.

1. The drill has variable speed control.

这钻机有变速控制。

来自《权威词典》

2. The variable weather is a great trial to me.

这种多变的天气真是让我受不了.

来自《简明英汉词典》

3. He is of a variable mood ; he never finishes what he starts.

他这个人朝三暮四,做起事来总是虎头蛇尾.

来自《现代汉英综合大词典》

4. Speed was a variable in the experiment.

在该实验中速度是个变数.

来自《简明英汉词典》

5. The speed of the windscreen wipers is variable.

汽车挡风玻璃上雨刷的速度是可变的.

来自《简明英汉词典》