W: (adj) unchangeable [Indirect via changeable] (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"
S: (adj) fluid, runny (characteristic of a fluid; capable of flowing and easily changing shape)
S: (adj) fluent, fluid, liquid, smooth (smooth and unconstrained in movement) "a long, smooth stride"; "the fluid motion of a cat"; "the liquid grace of a ballerina"
S: (adj) fluid, liquid (in cash or easily convertible to cash) "liquid (or fluid) assets"