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

1) unchanging, unvaried, eternal, permanent, fixed, stable; unchangeable, immutable, unalterable, inevitable, uniform: We studied photographs of the changeless Martian landscape. The fundamental truths of the Gospel are changeless. 2) abiding, permanent, constant, perpetual, everlasting, steadfast, unvarying, unchanging: Nothing could alter my changeless love for you.