Synonyms for Variable:

adj.

capricious (adjective)
changeful, flighty.
changeable (adjective)
unsettled, alterable, inconsistent, convertible, irresolute, Transposable, inconstant, fluid, varying, precarious, movable, modifiable, unsteady, adjustable, Vicissitudinous, volatile, unstable, changeful, vacillating, fickle, flighty, reformable, adaptable, flexible, mutable, changeable, ever-changing, wavering, versatile, restless, shifting, mercurial, transformable, protean, unpredictable.
changing, changeable (adjective)
inconstant, mercurial, uncertain, wavering, irregular, unsteady, capricious, mutable, shifting, volatile, fluid, ticklish, unsettled, fitful, fickle, flexible, changeful, vacillating, unstable, protean, temperamental, fluctuating.
different (adjective)
various.
irregular (adjective)
capricious, asymmetric, eccentric, uneven, erratic, fluctuating, unrhythmical, sporadic, jerky, unsystematic, fitful, intermittent, desultory, inconstant, irregular.
temperamental (adjective)
temperamental.
uncertain (adjective)
wavering.

n.

algorithm, computational, calculation, binomial, countdown, decimal place, deviation, abacus, approximation, average. change, various, short-lived, variant, temporary, short-term, floating, transient, fleeting, brief, passing. continue, conflicting, ticklish, temperamental, unlike, distinct, fantastic, freakish, different, inconsistent, contrasting, dissimilar, fantastical, divergent, whimsical, unpredictable, alternative, diverse. nature, factor, patchy, spotty, peculiarity, quality, feature, property, same, aspect, component, facet. variable (noun)
changeable, versatile, unsettled, varying, variable star, variable quantity, shifting, varied, protean, adaptable, uncertain.

Other synonyms:

short-term, transient, fleeting, short-lived, floating. passing, spotty, patchy. variant, whimsical, fantastical, temporary, temperamental. brief, ticklish, freakish. fantastic. random
unpredictable.
Other relevant words:
distinct, change, fantastical, patchy, unpredictable, temperamental, passing, floating, ticklish, spotty, variable star, various, freakish, transient, fantastic, varied, temporary, variable quantity, uncertain, divergent, variant, whimsical, inconsistent, different, brief.

Usage examples for variable

  1. It is not good for us, however it may be so for great statesmen, that we should be treated with variable politics. – The Works of the Right Honourable Edmund Burke, Vol. VI. (of 12) by Edmund Burke
  2. She found her states of mind exceedingly variable – The Allen House or Twenty Years Ago and Now by T. S. Arthur