Definition of: variable

(vâr′ē·ə·bəl) adjective
1. Having the capacity of varying; alterable; mutable.
2. Having a tendency to change; not constant; fickle.
3. Having no definite value as regards quantity.
4. Biol. Prone to variation from a normal or established type: said of plants and animals. See synonyms under FICKLE, IRREGULAR, MOBILE¹.
—noun
1. That which is liable to change.
2. Math. a A quantity susceptible of fluctuating in value or magnitude under different conditions. b A symbol representing one of a group of objects.
3. Meteorol. A shifting wind or winds; also, in the plural, places where such winds are common. [<OF <L variabilis <variare VARY]
—var′i·a·bil′·i·ty, var′i·a·ble·ness noun
—var′i·a·bly adverb