smoothness

noun3

1. •
   The condition of being smooth; the degree or measure of said condition.

   • With it,^([a pavement profile]) paving operations can be adjusted "on the fly" to maintain or improve smoothness. — 2013
2. •
   The highest order of derivative (the differentiability class) over a given domain.

   • Smoothness can vary from 0 (for a nondifferentiable function) to infinity (for a smooth function).
3. •
   The quantity measured by the modulus of smoothness.