The Oxford Thesaurus An A-Z Dictionary of Synonyms - invariableadj.

1) unchanging, changeless, unvarying, invariant, unwavering, constant, steady, stable, regular; fixed, fast, set, rigid, uniform, unfailing, unexceptional: She is invariable in her opinion of a woman's right to abortion. His invariable routine calls for a dawn swim, regardless of the weather. 2) immutable, unchangeable, unalterable, unmodifiable: The law of supply and demand is invariable. 3) permanent, fixed, enduring, abiding, eternal, unaltered, unvarying, unchanged, unvaried, unaltered, unmodified: The positions of the stars appear to be invariable.