Adjective changing, changeable
Synonyms: capricious, changeful, fickle, fitful, flexible, fluctuating, fluid, iffy, inconstant, irregular, mercurial, mobile, mutable, protean, shifting, shifty, slippery, spasmodic, temperamental, ticklish, uncertain, unequable, unsettled, unstable, unsteady, vacillating, volatile, waffling, wavering, yo-yo
Antonyms: invariable, unchangeable, unchanging, unvarying