variable
var-i-a-ble
noun
A factor, quantity, or item that can change or be changed.
"Temperature is a key variable in the experiment."
adjective
Likely to change or be changed; not consistent or fixed.
"The British weather is notoriously variable."
Thesaurus
Synonyms: variable quantity, varying, varied, shifting, changeable, uncertain, multivariate, unsettled, protean, covariant, variant, versatile
Antonyms: invariable