- unchangeable - not changeable or subject to change; "a fixed and unchangeable part of the germ plasm"-Ashley Montagu; "the unchangeable seasons"; "one of the unchangeable facts of life"
Antonyms: changeable, changeful, adjustable, astatic, checkered, distortable, erratic, fickle, mercurial, quicksilver, unstable, fluid, jittering, kaleidoscopic, kaleidoscopical, open-ended, quick-change, reversible, volatile, mobile