1. Not subject or susceptible to change or variation in form or quality or nature
   "The changeless traditions had endured for centuries";
   - immutable
    
2. Unvarying in nature
   "The changeless rhythm of the waves";
   - constant, invariant, unvarying
    
3. Remaining the same for indefinitely long times
   "The changeless laws of nature";
   - unalterable

See also: invariable, unchangeable

Antonym: changeable

Encyclopedia: Changeless