As a Noun: 1. In linguistics, an feature or item of language which has various forms (variants). The different forms of the variable may be related to differences in sociolinguistic variation in signed vocabulary and grammar. English = variant. 2. In mathematics, a quantity which during a calculation is assumed to vary or be capable of varying in value. English = variable. As a Verb or Adjective: 1. To be likely to change at any time. English = (be) variable. 2. To change in size, amount, or degree; for one thing to change in size, amount, or degree when another thing changes. English = vary. 3. Of a person's mental or physical state, to be constantly changing from better to worse. Overall, it is not very good. Idiomatic English = (be) up and down, (be) so so, (be) fifty-fifty. As Modifier: 1. In mathematics, used to describe a quantity able to assume different numerical values. English = variable (quantity).