quality - an essential and distinguishing attribute of something or someone; "the quality of mercy is not strained"--Shakespeare

inhomogeneity - the quality of being inhomogeneous

fitfulness, jerkiness - the quality of being spasmodic and irregular

intermittence, intermittency - the quality of being intermittent; subject to interruption or periodic stopping

wavering, fluctuation - the quality of being unsteady and subject to fluctuations; "he kept a record of price fluctuations"

haphazardness, stochasticity, randomness, noise - the quality of lacking any predictable order or plan

unevenness, variability - a quality of variability and lack of uniformity

unsteadiness - the quality of being unsteady--varying and irregular