a condition in which everything is regular and unvarying
source: WordNet 3.0
the quality of lacking diversity or variation (even to the point of boredom)
source: WordNet 3.0
The quality or state of being uniform; freedom from variation or difference; resemblance to itself at all times; sameness of action, effect, etc., under like conditions; even tenor; as, the uniformity of design in a poem; the uniformity of nature.