- changeless, constant, invariant, steady, unvarying - persistent in occurrence and unvarying in nature; "maintained a constant temperature"; "a constant beat"; "principles of unvarying validity"; "a steady breeze"
Antonym: variable (indirect, via invariable)
- unvaried, unvarying - lacking variety
- uniform, unvarying - always the same; showing a single form or character in all occurrences; "a street of uniform tall white buildings"