noun, noun which may take the genitive case particle 'no'
irregularity; unevenness; asymmetry; lack of uniformity
Describes a state of being not uniform, not equal, or not symmetrical. Often used in formal or technical contexts, such as describing shapes, surfaces, or distributions.
この地形は不斉で、平らな部分が少ない。
This terrain is irregular, with few flat areas.
不斉な分布がデータに見られる。
An uneven distribution can be seen in the data.
不揃い emphasizes things not matching or being of different sizes/shapes in a set, while 不斉 is more about lack of uniformity or symmetry in a single entity or pattern.
不均一 is a more technical term for 'heterogeneity' or 'non-uniformity', often used in scientific contexts. 不斉 is broader and can be used for physical irregularity.
Compound of 不 (fu, 'not') and 斉 (sei, 'equal' or 'uniform'). The spelling 不整 uses 整 (sei, 'order') instead, with a similar meaning. The exact historical derivation is uncertain, but the word follows a common Sino-Japanese pattern of negation.