adjective / noun
invariable
in-VAIR-ee-uh-buhl/ɪnˈveriəbl/
Remaining unchanged across circumstances.
The standing stone remains invariable while the seasons change around it.

Etymology
The negative prefix turns “changeable” into “not changeable.” This describes constancy or uniformity: something invariable stays the same rather than differing.
In context
it is an invariable fact that dragons are extremely Vigilant they never sleep
More examples
- The laboratory maintains an invariable temperature throughout the test.
- Sunday dinner is an invariable part of our family routine.
- An invariable keeps the same form in different grammatical contexts.
Forms
invariable · invariables
invariably adverb — Always, without exception or variation.
invariability noun — The quality of remaining unchanged across circumstances.