the.com/unevenness
The state of things refusing to agree on a single height.
means The quality of being not smooth, level, or uniform, whether in surface, distribution, or quality.
from From Old English efen, meaning level or equal, with un- to negate and -ness to nounify it — literally not-equal-ness made tangible.
Triple suffixUn, even, and ness stacked like layers.
Physics nameSurface unevenness is measured as roughness in microns.
Beyond surfacesAlso describes uneven wealth, sleep, and effort.