Uniformity

Noun

1. The quality or state of being uniform.

   "The uniformity of the decor"

2. The quality or state of having the same characteristics or form as other things, and lacking variety; an instance of this.
3. Often followed by of: the quality or state of a thing always having the same characteristics or form; consistency or regularity in appearance or operation.

   "The uniformity of the decor"

4. Often followed by of: especially of one's life: lack of variety; tedious sameness; monotony.
5. The condition or state described by uniformitarianism (“the scientific principle that natural laws and processes operated in the past in the same way and at the same rates that they operate today, and sometimes in the same way everywhere in the universe as well”).