Gradient

1. The rate of regular or graded ascent or descent in a road; grade.
2. Moving by steps; walking; as, gradient automata.
3. A part of a road which slopes upward or downward; a portion of a way not level; a grade.
4. Rising or descending by regular degrees of inclination; as, the gradient line of a railroad.
5. The rate of increase or decrease of a variable magnitude, or the curve which represents it; as, a thermometric gradient.
6. Adapted for walking, as the feet of certain birds.