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"
changeless -
unvarying in nature; "maintained a constant temperature"; "principles of unvarying validity"
invariable not liable to or capable of change; "an invariable temperature"; "an invariable rule"; "his invariable courtesy"
changeless -
not subject or susceptible to change or variation in form or quality or nature; "the view of that time was that all species were immutable, created by God"
